LIBRARY OF CONGRESS. 

Chap. -.L-.r Copyright No. 

Shelf..i.2i.^ 

UNITED STATES OF AMERICA. 



CRUDE RUBBER 



AND 



Compounding Ingredients 



A TEXT-BOOK OF 
RUBBER MANUFACTURE 



By HENRY C. PEARSON 

Editor of The India Rubber World 



NEW YORK AND LONDON 

The India Rubber Publishing Company 

1899 



•ECOND OOPY, 






41338 

Copyright, 1899, By Henry C. Pearson. 



..lH^ 1889 ) 

^ii^ of Co^'C^ 



ix^X^y 



/ 







-tfk^V 



i 



^1 



To my friend and partner, 

JOHN ROBERTSON DUNLAP, 

In token of warm personal regard and high appre- 
ciation of his brilliant and sterling 
qualities, 

THIS BOOK IS DKDICATe;d. 



PREFACE. 

In its beginning, this volume was simply a brief, conve- 
niently arranged portfolio of facts concerning the various ingre- 
dients that enter into rubber compounds. It was designed for 
the author's use alone. Certain rubber manufacturers, however, 
learning of its existence, and desiring copies of it, urged strongly 
that the matter be published and given to the trade as a whole 
in book form. The superiority of such a collection over the most 
comprehensive book of compounds doubtless will be apparent to 
the expert manufacturer, for this reason. When a manufacturer 
buys a set of compounds — and most of them are purchasable — 
he invariably acquires them not so much for use as for sugges- 
tion and comparison. The descriptions, therefore, of a great 
majority of the ingredients used in all lines of rubber com- 
pounding, and scores with which he may be unfamiliar, will 
be so suggestive to the practical man that new sets of com- 
pounds will be secured, each partaking of the individuality of 
the expert, and bearing the impress of the line of work done 
in the factory to which he is attached, and wholly free from the 
taint of imitation or counterfeiting, which is the bane of the pur- 
chased secret. It is felt that another point of supei lOrity over the 
mere compound book will be found in the fact that no private for- 
mulas are given, which might wound the feelings of the more 
conservative manufacturers. 

The higher level of prices for crude rubber which has pre- 
vailed for some time past is drawing the attention of manufactu- 
rers to the pseudo gums — such, for instance, as Pontianak. A 
number of these are described in this volume, with the hope that, 
since their presence in the market depends largely upon the in- 
sistence with which rubber manufacturers demand them from im- 
porters or gatherers, many more may be made generally useful. 
Another line of endeavor that already has been fruitful of ex- 
cellent result is in the production of rubber substitutes. It is 
hoped that the chapters upon this subject, covering some two 
hundred varieties, some excellent and others perhaps of little 
value, may prove of such service that, even if the ideal substitute 



6 PREFACE. 

does not materialize, the knowledge of the scope of the substi- 
tutes already known will be so increased that their intelligent use 
will be greatly amplified. 

In the compilation of this book free use has been made of 
English, German, and French standard technical works as well as 
of technical journals, such as The India Rubber World, The India- 
Riibber and Gntta-Percha Trades Journal, the Gummi-Zeitung, 
The Journal of the Society of Chemical Industry, and others. 

The author takes pleasure in acknowledging his indebted- 
ness for helpful suggestions to skilled manufacturers and super- 
intendents in both America and Europe, and to the following dis- 
tinguished writers on rubber topics : P. G. W. Typke, F, C. S. ; G. 
S. Jenman, Government Botanist and Superintendent of the Bo- 
tanic Gardens, Demerara ; William Thompson, F. R. S. E. ; H. 
Grimshaw, F. C S. ; W. Lascelles-Scott, F. R. M. S., M. S. C. I. ; 
Richard Gerner, M. E. ; Dr. C. Purcell Taylor, Thomas Bolas, F. 
C. S., F. L C. ; Professor D. E. Hughes, F. R. S. ; Messrs. Hein- 
zerling and Pahl, Berlin; Granville H. Sharpe, F. C. S. ; Carl Otto 
"Weber, Ph. D. ; A. Camille, J. H. Hart, Superintendent Botanic 
Gardens of Trinidad; Dr. D. Morris, M. A., C. M. G., Commis- 
sioner of the Imperial Agricultural Department for the West In- 
dies; the late Dr. Eugene F. A. Obach, F. I. C, F. C. S., M. E. 
E. E. ; Professor F. A. C. Perrine, D. Sc, and many others. 

I also wish to express my appreciation of the valuable assis- 
tance given me on the chapters devoted to crude India-rubber 
and Gutta-percha, and the assistance in editing and revising other 
portions, by my associate editor on The India Rubber World, Mr. 
Hawthorne Hill. 

Boston, June, 1899. HENRY C. PEARSON. 



CONTENTS. 



CHAPTER I. 

Grades of Crude Rubber, Sources of Supply, and Physical Charac- 
teristics ; Para, Central, African, and East Indian Gums ; Ori- 
gin of Trade Names ; Botanical Details 9 

CHAPTER 11. 

Some Little Known Rubbers and Bastard or Pseudo Gums ; Possi- 
bility of Development of their Use in the Factory 24 

CHAPTER III. 

(i) Divisions in Rubber Manufacture and Primary Processes in 
Manipulating the Gum. (2) The "Washing, Mixing, and Calen- 
dering of Rubber ; Knowledge of Gathering Processes Essen- 
tial to Intelligent Manipulation in Manufacture 34 

CHAPTER IV. 

Vulcanizing Ingredients and Processes ; Sulphur, Antimony, Sul- 
phides, and Other Materials Used 49 

CHAPTER V. 

Fillers and Other Ingredients Used in Dry Mixing in Rubber 
Compounds; Sources, Properties, and Uses of the Various 

Materials 60 



CHAPTER VI. 

(i) Substitutes for India-rubber and Gutta-percha. (2) Substitutes 
for Hard Rubber and Gutta-percha. (3) Celluloid and Cellu- 
lose Products. (4) Miscellaneous Substitutes and Compounds ; 
History of their Use, and Description of their Properties 87 



8 CONTENTS. 

CHAPTER VII. 

Resins, Balsams, Gums, Earth Waxes, and Gum-like Substances 

Used in Rubber Compounding 115 

CHAPTER VIII. 

Coloring Matters. Reds, Blacks, Yellows, Greens, Blues, and Other 

Colors in Hard and Soft Rubber 133 

CHAPTER IX. 

Acids, Alkalies, and Their Derivatives Used in the Rubber Manu- 
facture 149 

CHAPTER X. 

Vegetable, Mineral, and Animal Oils Used in Rubber Compounds 

and Solutions 168 

CHAPTER XI. 

Solvents Used in India-rubber Proofing and Cementing and in 
Commercial Cements ; Their Origin, Properties, and Methods 
of Use 181 



CHAPTER XII. 

Miscellaneous Processes and Compounds for Use in the Rubber Fac- 
tory ; Waterproofing Compounds 195 

CHAPTER XIII. 

Physical Tests and Methods of Analysis of Crude Rubber ; Specific 
Gravity ; Analysis of Vulcanized Rubber ; Solubility and 
Permeability of Rubber ; Cravenetting ; Deodorizatian ; De- 
terioration ■ 215 

CHAPTER XIV. 

Gutta-percha : Its Sources, Properties, Manipulation, and Uses ; 
Components of Gutta-percha ; Vulcanization ; Gutta-percha in 
Compounds ; Methods of Analysis 228 



CHAPTER I. 

GRADES OF CRUDE RUBBER, SOURCES OF SUPPLY, AND PHYSICAL 

CHARACTERISTICS. 

Caoutchouc or India-rubber is a product of a great variety 
of trees, vines, and shrubs, most of which grow in the torrid zone. 
Central America, South America, Africa, and India all furnish 
their quota, and while the gum that comes from these vast areas 
is all rubber, it differs widely in its characteristics, due in a meas- 
ure to a variety of methods in gathering and coagulation, but 
more specifically in its chemical constituents. South America 
produces the best rubber in the world and the most of it. The 
Amazon valley, embracing hundreds of thousands of square miles 
of rubber forests in Brazil, Bolivia, and Peru, is the center of the 
industry, the product being exported from the city of Para, 
whence the name "Para rubber." Two or more species of the 
Hevea produce this rubber, the best known being the Hevea Bras- 
iliensis. Peru also produces a rubber, lower in grade than Para, 
known as "Caucho." The Castilloa elastica, the rubber tree of 
Nicaragua and other Central American states, which is also found 
in Ecuador, Venezuela, Colombia, and Mexico, produces the rub- 
ber known as "Centrals." The Atlantic states of Brazil, south of 
Para, produce other rubber trees, from which come the grades 
known as "Mangabeira," "Pernambuco," and "Ceara." Africa 
ccmes next to South America in the amount of rubber produced, 
and in the interior of that continent, as in the Amazon country, 
there are great rubber forests as yet untouched. African rubber 
is inferior to that obtained from South America, but through im- 
proved processes in gathering and curing, the various sorts are 
delivered in much better condition year by year. African rubber 
is found on both the east and west coasts and throughout the great 
basin of the Congo river and also on the island of Madagascar. 

The Landolphia, of which there are several species, is a giant 
vine or creeper from the milk of which most of the African rub- 
bers come. Rubber from Lagos and from some other colonies in 
West Africa, however, is obtained from a tree known ■ as the 



lo GRADES OF CRUDE RUBBER. 

Kickxia Africana. The East Indies to-day furnish but little 
rubber. The first rubber exported from that part of the world 
came from Assam. In time, however, Burma became a producer 
of a similar grade, known as "Rangoon" rubber. The principal 
source of rubber in that part of the w^orld is a tree known as the 
Ficus elastica. The islands of Java and Borneo and also Penang 
and other states in the Malaysian peninsula produce a certain 
amount of rubber. 

Seaports, trading posts from which the first shipment is made, 
the name of a colony or country, or descriptive terms, as "thim- 
bles," "buttons," "strips" — all or any of these may serve for names 
of different grades of crude rubber. A complete market report 
w^ould indicate that there are a great number of different qualities 
of rubber, many coming from the same source. This, however, 
is not wholly true. Take, for instance, the Para grades : years 
ago any rubber coming from Brazil was called Para rubber. Later 
it was divided into "fine," "medium," and "coarse." Then the 
rubber from the islands in the lower Amazon became known as 
"Islands rubber," while that coming from further up stream was 
known as "Upriver," and these, too, were divided into fine, me- 
dium, and coarse. Now a dozen or more local names are applied 
to rubber from different localities, tributary to the Para market. 
At the same time, most of these rubbers sell at the same figures, 
grade for grade, with the exception of coarse. 

Something like this is true in the African rubber trade. For 
instance, a great number of local names are applied to the Congo 
rubber. The difference between "Equateur," "Kassai," and 
"Lopori" sorts may not be greater than between different lots from 
the same place. With a very few exceptions, the names which 
follow are those used commonly in the leading markets : 

PARA RUBBER. 

Rubber is classified atParaandManaos into three grades, des- 
ignated by the Portugese words Una, entraiina, and sernamhy. 
These same grades in the United States are known as "fine," "me- 
dium," and "coarse," while in England they are classified as "fine," 
"entrafine," and "negroheads," the latter being divided to provide 
for a subgrade, "scrappy negroheads." The production is about 60 



PARA RUBBER. ii 

per cent, of fine, 13 per cent, of medium, and 27 per cent, of coarse. 

Fine Para rubber comes in large bottles and, when cut, shows 
a surface closely marked with lines, corresponding to the number 
o{ layers of rubber milk added during the smoking process. These 
layers are easily separated and, when stretched, are very transpar- 
ent. This rubber smells not unlike smoked bacon. 

Medium or Entrafine resembles ''fine," but is not so well 
cured, curds and globules of milk not perfectly smoked being 
found between the layers. 

Coarse or Sernamby is made up of the residue, scraped daily 
from the collecting vessels, or from milk which has curdled before 
it could be smoked and made into "fine." 

Besides this general classification of Para rubber, other names 
are in use, derived from the localities of origin. 

Islands rubber is that produced on the island of Marajo, 
some 17,500 square miles in extent, and other islands in its vic- 
inity in the delta of the Amazon, together with that from other 
parts of the state of Para, except the Xingu, Tocantins, and Tap- 
ajos rivers, which might well be called lower Amazon grades. 
These islands in a recent year yielded over 12,000,000 pounds, or 
63 per cent, of the total for the state of Para. The Islands 
"fine" and "medium" rubber is in the form of round or flat bot- 
tles, while the "coarse" or "sernamby" is in scraps massed into 
balls and round cakes, which gives the name "negroheads" to this 
grade in the English market. 

Caviana rubber, named from the island that produces it, is 
the highest grade of Islands, and is to-day marketed as a distinct 
sort. It has a smooth close grain, and is much in demand for fine 
work. 

Cameta rubber is so called from the port of that name, on the 
Tocantins river. It is noted for the superior quality of its "ser- 
namby" grade, the "fine" being the same as from the islands, but 
rarely seen. This rubber comes in the form of little cups pressed 
into large "negroheads." 

Upriver rubber includes the product of the country border- 
ing the Amazon and its tributaries above Para, and that which 
comes from Peru and Bolivia through the large streams rising in 
those countries — such rivers are the Purus, Jurua, Javary, and 



12 GRADES OF CRUDE RUBBER. 

Madeira. This rubber for the most part is derived from the 
Hevea discolor and comes to market in biscuits varying greatiy in 
size and shape, a full average biscuit weighing about thirty 
pounds. The rubber tree on the islands is more frequently the 
Hevea Brasiliensis, but it is a mooted question whether the differ- 
ence in the trees accounts for the difference in quality between 
Upriver and Islands rubber. "Upriver" rubber is marketed also 
under such local names as "Manaos," ''Madeira," "Bolivian," etc. 

Itaituba rubber comes from the port of that name, at the 
head of steam navigation on the Tapajos river, which enters the 
Amazon at Santarem. Rubber from this river is distinguished 
for the rather gutty quality of the "fine" and "medium," and its 
stringy, dirty "sernamby." 

XiNGU rubber from the Xingu river, is noted for the spe- 
cially good cure of the "fine." 

Manaos rubber is named from the city which is the capital 
of Amazonas, 1,200 miles up the Amazon river, and the center 
of the rubber trade of an immense district. Upriver rubber ex- 
ported direct to foreign markets from this port is sometimes des- 
ignated as "Manaos rubber." 

Madeira rubber, named from a great river which joins the 
Amazon below Manaos, is of excellent quality and produced in 
large quantities. It has a finer and closer grain than any other 
upriver rubber except the Bolivian. 

Bolivian rubber is floated down the Beni and other rivers 
in Bolivia to the Madeira, and thence to the Amazon. It meets 
innumerable detentions from cataracts in the upper Madeira, on 
account of which it becomes somewhat dried before reaching mar- 
ket. It has the further advantage of being cured by a better class 
of labor than is common in Brazil, of having a tougher fiber and 
of being cleaner than most upriver rubber, for which reasons it 
brings higher prices than any other. 

MoLLENDO rubber comes from southern Bolivia, being trans- 
ported by steamers across Lake Titicaca and by rail to Mollendo, 
a Peruvian port on the Pacific, and thence principally to England. 
It is prepared in biscuits and sheets and is marketed at a price 
between upriver and islands. 

Angostura rubber comes down the Orinoco in Venezuela, 



CENTRAL RUBBERS. 13 

from Cuidad Bolivar, which town formerly was known as Angos- 
tura. It is of the same grades as the Para sorts. Some of the 
same class of rubber finds its way into Brazil, at Manaos, where 
its identity is lost. 

Orinoco rubber is the same as "Angostura.^' 
Matto Grosso rubber is from the state of that name in the 
southwest of Brazil, and reaches the market partly through tribu- 
taries of the Amazon and partly through the Parana, which dis- 
charges into the river Plate. It comes in "fine," "medium," and 
"coarse," but principally the latter, little of it reaching the market 
at present, 

Caucho is a distinct sort of rubber, inferior to that from 
Para, collected along the Peruvian rivers tributary to the Amazon 
and particularly along the Javary. It is not cured by smoking, 
but by the admixture with the milk of lime, potash, or soap. The 
physical characteristics of Caucho in the main are the same as in 
the Central American rubbers. It is known also as "Peruvian 
rubber" or "Peruvian caucho." It is exported from IquitoS; Ma- 
naos, and Para, and included in the general total of rubber ex- 
ports from the Amazon country. It comes to market in three 
forms — Ball, Strip, and Sheet (or Slabs) — ranging in value in 
the order named. 

CENTRAL RUBBERS. 

Central American rubber, or "Centrals," includes that 
which is produced in all the states north of the Amazon valley, 
up to and including southern Mexico. It forms a distinctive class, 
being the product of a tree not found elsewhere. The consumption 
of Centrals in the United States was larger once than of Para rub- 
ber, but the yield has declined gradually to small proportions. 
This rubber is in good demand for certain uses, ranking in price 
below coarse Para. It has not the toughness or strength of fine 
Para, and possesses less elasticity. Centrals are classed usually 
as "sheet" and "scrap," besides which the terms "strip," "slab," 
"ball," and "sausage" are used. Greytown being a common ship- 
ping-point for Centrals, there is much confusion, one sort often 
getting substituted for another. Most of the yield of Costa Rica 
is exported through Nicaragua. The treatment of Centrals gen- 



14 GRADES OF CRUDE RUBBER. 

erally consists in heating the sap and stirring in a strong concoc- 
tion of the mik of bindweed, the product being "sheet" rubber. 
The rubber drippings which adhere to the bark of the tapped 
trees are peeled off when dry and called '"scrap." The trade names 
below apply to the locality of origin, rather than indicating dis- 
tinctions in quality. 

Nicaragua rubber includes more than the product of that 
republic. The real Nicaragua rubber is drier as a rule than other 
grades of Centrals. Nicaragua sheet comes to market in a less 
clean condition than formerly, and the scrap now brings a better 
price. 

Greytown scrap is the best grade of Nicaragua rubber. 

Guatemala rubber is inferior and unequal in quality. The 
best is whitish in color, and the lower grades black with a tarry 
appearance. It is said to be sometimes adulterated with cheap 
molasses. In curing, the rubber-gatherers pour the sap upon mats 
to dry, afterwards pulling off the product in sheets, pressing them 
together for shipment. 

Guayaquil strip^ from Ecuador, is imported in two grades 
— good and ordinary. Like the Guatemala rubber, the best has a 
whitish appearance. The inferior sort is porous and filled with a 
fetid black liquid, which carries an almost indelible stain. 

Esmeralda rubber, which also comes from Ecuador, is class- 
ed as a Strip and Sausage, the two grades coming to market in 
about equal quantities. 

Colombian is a pressed strip rubber, dark in color, some- 
times showing white when cut. It is graded "No. i" and "No. 2." 
Some of the rubber from Colombia bears local designations, be- 
sides varying in quality. These include: 

Cartagena, a strip rubber, dark and tough, graded "No. i" 
and "No. 2," selling at less than "Colombian." It comes also in 
thin sheets, rough or "chewed" in appearance, and tarry or sticky. 
The production has decreased very much of late. 

Panama rubber, like that from Nicaragua, embraces a wide 
range of quality. The Pacific mail steamers bring together at Pa- 
nama rubber from numerous ports, and confusion of grades is a 
result. What is marketed as "Panama" comes in "sheet" and 
"strip." 



AFRICAN RUBBER. 15 

Tumaco comes in "sheet," "slab/' and "scrap," from the Pa- 
cific coast of Colombia. Very little of it is received. 

Mexican rubber is of fair quality, but is received in constant- 
ly decreasing quantities. The grades, listed in the order of their 
selling value, are Ball, Strip (or Scrap), and Slab. 

Tuxpam strip comes from the Mexican port of that name. 
Very little of it is received, and that not of uniform quality. 

Honduras strip is of a quality similar to the Mexican, but 
is little produced. 

West Indian rubber has a good reputation for quality. It is 
not produced on the islands, but comes from Venezuela and Cen- 
tral America, and is simply a general trade name used in England. 

The grades which follow, though not entitled geographically 
to be included as "Centrals," are in fact so classed, on account of 
their quality. 

Mangabeira rubber is so called from the local name of the 
tree producing it, in the Atlantic states of Brazil, south of Para. 
It is an alum-cured rubber and comes in sheets, which resemble 
slices of liver and are of a tawny red color. The thin sheet sells 
for more than the thick, as it is dryer and better cured. Occasion- 
ally it comes in the form of balls. It is exported from Pernam- 
buco, Bahia, Natal, and other points on the coast. 

Pernambuco is another name for Mangabeira rubber, deriv- 
ed from the principal state and port from which it is shipped. 

Ceara rubber comes from a tree particularly abundant in the 
Brazilian state of Ceara and is marketed principally in England. 
The sap exudes from the tree and coagulates in the form of "tears" 
which are gathered in scraps and balls. There are three grades, 
the lowest of which is dirty and difficult to use. Ceara rubber is 
deficient in elasticity and is hard to vulcanize. It is very dry and 
free from stickiness. 

AFRICAN RUBBER. 

African rubbers, though comparatively late in becom- 
ing known, are produced now in quantities second only to the sup- 
ply from the Amazon. As a class they are more adhesive and less 
elastic than Para rubbers, ranking with or below Para negroheads. 
They often contain a liberal percentage of impurities, and for a 



iC GRADES OF CRUDE RUBBER. 

long time their disagreeable odor and intractable nature hindered 
their introduction. But advancing prices for Para grades and fear 
of their coming scarcity led manufacturers to experiment with 
African rubbers, until many uses were found for them. The re- 
sult has been a temporary check in the upward tendency in price 
of the Para grades, although there are many purposes for which 
Africans never have been considered as competing with them. At 
the same time, the possibilities in the way of utilizing African 
sorts have not been exhausted, each year bringing out new uses. 

The African rubbers are obtained from giant creepers, of 
which there are a dozen species on the continent and in the island 
of Madagascar, and also from several trees, the most important 
one of which abounds on the Gold Coast, in Lagos, and some other 
West Coast colonies. The adulteration of African rubbers is not 
uncommon, being due to the dishonesty, not only of the native 
gatherers, but doubtless also of some foreign traders on the coasts. 
But in several of the English and Belgian colonies stringent laws 
have been passed to prevent such adulterations. On the Gold 
Coast the lumps of rubber brought to market by the natives were 
formerly cut into strips or buttons by machinery, before being ex- 
ported. To-day this work is done in England, the rubber then 
being known as "Liverpool pressed." It has been urged by some 
importers of Lagos rubber that wilful adulteration by the natives 
is rare. Rubber has been worked in Lagos for only about four 
years, so that many of the workers there are yet inexperienced and 
lacking in skill. Even in the Gold Coast Colony, where the indus- 
try began ten years earlier, a certain percentage of the rubber is 
spoiled in gathering. 

The milk of the Landolphia vines, the chief rubber producers 
of Africa, coagulates on exposure to the air, though in some locali- 
ties use is made of various astringents, boiling in water, and other 
methods to assist in preparing rubber. Even where these methods 
are used, a residue of the rubber sap is left to dry on the bark 
and in the earth, and is gathered in strings or scraps. The only 
treatment in some other places is the smearing of the sap upon the 
bare bodies of the natives, where it dries speedily in the sun, and is 
easily peeled off. 

Ball is the classification of a larsfe share of the African rub- 



AFRICAN RUBBER. 17 

bers, which comes in every size from three or four inches in dia- 
meter down to half an inch or less. "Small ball" of the several 
kinds differs from the "large ball" in size, and is also dryer and 
affords a smaller degree of shrinkage. 

Thimbles. — The natives, after gathering this rubber, cut it 
into cubes, about an inch square or less. Thimbles contain bark 
and sand, but very little moisture. 

Nuts. — Rubber thimbles from Ambriz are quoted sometimes 
in European markets as "Ambriz nuts." 

Lump rubber comes in large pieces, varying in size and of 
irregular shapes. When packed in casks the pieces often become 
massed together in transit. It is from the best of the lump rubber 
that the most desirable buttons and strips are made. 

Flake comes in lumps, livers, and soft irregular masses, and 
is valuable in the factory chiefly for frictions and for softening 
compounds. 

Paste is the same as "Flake." The Accra flake and Niger 
paste, which are the same in quality, are at the foot of the list, in 
respect to prices, the Niger being the cleaner. 

Strips are lump rubber that is sliced and pressed by machi- 
nery before it is offered to the trade. 

Buttons is a name applied to rubber similarly treated as in 
making strips, except that it is cut into small pieces, whereas strips 
have been marketed in every length up to ten feet. 

Biscuits is another name for "Buttons." 

Oysters is another name for "Buttons" or "Biscuits." 

Tongues. — Some rubber formerly came to market in long, 
narrow, tongue-shaped pieces. The same grades are now more 
frequently seen in the shape of large balls. 

Niggers are of various sorts and from different sources. 
These rubbers are ball-like in some cases, having the appearance 
of masses of stringy rubber pressed together between the hands 
and wound into compact masses. 

Twist rubber is not unlike "Niggers" in quality, but shows 
less shrinkage and differs in preparation and appearance. The 
string or strip-like pieces are wrapped about each other in order 
to give a twisted look to the balls. 

The list of rubber grades which follows is based upon a geo- 



i8 GRADES OF CRUDE RUBBER. 

graphical arrangement, beginning with the upper west coast of 
Africa : 

GAMBIA. 

Gambia Niggers (No. i, No. 2, No. 3). — These are classified 
according to cleanliness, No. i and No. 2 being fairly clean, and 
No. 3 containing considerable soil. 

Bathurst. — Same as Gambia. 

SIERRA LEONE. 

Sierra Leone Twists (No. i. No. 2, and rejections). — This is 
white and amber in color, of low shrinkage, and has bark and grit 
in it, but little moisture. 

Niggers (No. i. No. 2, No. 3) are quite moist. No. 2 and 
No. 3 contain considerable soil. 

Cake. — Fairly clean, but wet. It is both red and white, the 
former bringing the better price. 

Manoh Twists. — This comes in the shape of tightly wound 
cords of rubber and works soft. In color it is black or white, the 
black being the best. 

LIBERIA. 

Liherian. — This is graded as Lump, Hard Flake, and Soft. 
It cuts yellow, is very wet, and is often a soft pasty rubber. 

ASSINEE. 

What is known as Assinee is graded as follows: Assinee- 
Silky, Grand Bassam, Attoahoa, Lahou, Bayin, Half Jack. It is 
like Old Calabar, only it comes in chunks three inches square, is 
wet, and cuts yellow. These names are chiefly used in the English 
market. 

GOLD COAST COLONY. 

Gold Coast. — This is chiefly lump from which Strips and But- 
tons are made. There are also Biscuits and Niggers (hard and 
soft). The Flake is wet and has a bad smell, but otherwise is quite 
clean. 

Accra. — The Accra lump furnishes Strips and Buttons and is 
graded "prime," "seconds,'' and "thirds." The lower grades are 
Flake and Paste. 

Cape Coast. — This is another lump from which Strips and 
Buttons are manufactured and has for lower grades Flake and 
Soft. 



AFRICAN RUBBER. 19 

Salt Pond. — This Lump is also used in Strips and Buttons, 
the lowest grade being Flake. 

Addah Niggers (graded as No. i and No. 2) is very similar 
to Sierra Leone, but generally in smaller balls. It is not an Accra 
rubber, nor are Quittah Niggers or Axini. As a matter of fact, 
the grades from these different ports differ little if any, and are 
sold most frequently under the head of "Accra" rubber, from the 
name of the principal town in the colony. 

TOGOLAND. 

Lomi (or Lome) Ball. — The best grade of this is a clean, firm 
rubber and is fairly dry. The lower grades are rarely seen. 

LAGOS. 

Lagos. — This Lump is also turned into Buttons and Strips, 
while soft inferior lumps are sold without manufacturing, as low 
grades. It is very easily distinguished from Accra by its odor. 

NIGER RIVER PROTECTORATE. 

Niger. — The chief grade is Paste, which has an acid smell and 
is a low grade pasty rubber, wet but clean. 

Old Calabar. — It is graded as Blue, Lump, and Niggers and 
is very bad smelling. The best lump is undoubtedly used for strips 
and buttons. 

Benin Ball. — Is generally dirty and has a rotten, woody smell. 

CAMEROONS (OR KAMERUN). 

Cameroons. — The Ball is graded as large, mixed, and small ; 
the Clusters, which contain some fifty balls, as No. i and No. 2 ; 
and the Knucklj^ ball, which is a small dry ball. This rubber has 
a fairly strong smell. 

Batanga Ball ("B," "E'^). — Same as Cameroons, Batanga be- 
ing the name of a river and country in the Cameroons. 

FRENCH CONGO. 

French Congo rubber is very similar to Cameroon, but the 
balls are larger, 

Gaboon is the best known flake and has for additional grades : 
Lump, Large "O" Ball, and Small "O" Ball. The Flake is free 
from dirt and is soft. 

Mayumba is both Ball and Flake. Another grade known as 
Mixed is a combination of the two and is sold as second quality. 

Loango. — Ball. 



20 GRADES OF CRUDE RUBBER. 

These are names of rubber stations on the coast. The natives 
boil rubber milk, adding the juices of vines, and, while the rubber 
is hardening, wind it into balls, weighing from one-fifth pound to 
three pounds. The best rubber is not boiled, the milk drying on 
the wrists of the natives, as they tap the rubber vines. At the coast 
the balls are cut, to detect any cheating, and washed and packed in 
casks for export. 

CONGO FREE STATE. 

Congo rubber comes in the shape of Buttons, Balls (No. i 
and No. 2), Red Thimbles, and Black Thimbles. The Ball is simi- 
lar to Cameroons, but tougher. The Dutch Congo Ball is the same 
as the Congo Ball, but is known as the best grade of that rubber. 
There is also the Congo (Kassai), Black Twist (graded as fine, 
mixed, and secondary), and Red Twist. The Strips are among 
the toughest of African rubbers and are dry, with a woody smell. 

From the Lower Congo comes also the Luvituku, which is a 
Red Ball rubber, and from the Upper Congo, the following: 

Upper Congo. — Ball, Red Ball, Twists, and Strips, all of 
which is good tough rubber. 

Uelle. — Strips, usually heated and fermented and bad smell- 
ing; Cakes, wet, but clean. 

Sankuni. — Ball, very similar to Congo Ball. 

Lake Leopold. — Graded as Sausage and Ball. It does not 
dififer from the foregoing enough to warrant special description. 

Equateur. — In the form of balls (small and mixed). It is 
dark, dry, and clean, but contains some fermented rubber, which 
smells badly. 

Lopori. — Graded as Ball (large and small). Strips, and Cakes. 
Some of the balls are fine and clean, while others contain fermented 
milk. Lopori also comes as Sausage. 

Bangui. — Comes in the form of strips and is a firm, tough 
rubber. 

Bussira. — Ball ; a trifle softer than Lopori, but usually of ex- 
cellent quality and dry. In use it develops a strong smell. 

Aruivimi. — Ball. This usually comes as large, firm balls, 
but on cutting them open much of the interior is found fermented. 

Mongalla. — In this the Ball is similar to Upper Congo Red 
Ball. It also comes in Strips, and is a good rubber. 



AFRICAN RUBBER. 21 

Bumba. — Ball ; Buki — Ball ; Tava and Kwilu are all good Up- 
per Congo grades that are not distinctive enough to dwell upon. 

Wamba. — This is a grade of Thimbles and is a good black 
rubber, with only ordinary shrinkage. 

ANGOLA. 

Benguela. — Graded as Sausage and Niggers. Of the latter, 
No. I is clean and tough, and No. 2 contains a large percentage 
of red leaf. 

Loanda. — In this the grades, which are Sausage and Nig- 
gers, are similar to Benguela, but not so dry. There are also 
Twists (red and black). 

Ambriz. — Chiefly Thimbles or Nuts ; both are poor grades. 

EAST AFRICA. 

Mozambique rubber is that coming from the port of Mozam- 
bique, from other ports in the same colony, and perhaps from still 
other East African ports. It possesses some properties in com- 
mon with the Madagascar rubbers. The rate of shrinkage is less 
than in most African sorts, and good prices are obtained. In the 
Liverpool market, which is the best for Mozambique grades, quo- 
tations are made for Orange Ball, Ball No. i. Ball No. 2, Ball No. 
3, Liver, Sausage, Root, Sticks or spindles, Sticks removed. Un- 
ripe. 

The Orange Ball (resembling an orange in size and shape) 
is the choicest rubber. Other grades of Mozambique Ball are 
distinguished further as "white" and "red," the latter being in- 
ferior. Its reddish color is due to the fine bark mixed with it. 
The Unripe contains more bark than rubber, and is not thoroughly 
cured. 

Sticks or spindles consist of spindle-shaped pieces made of 
slender strings of rubber wound around a bit of wood. Liver 
(or cakes) is in smooth pieces of irregular size. 

Lamu Ball, Liver, Sausage, and Root come from the Mozam- 
bique port of this name. They are not rubbers of a distinctive sort. 

MADAGASCAR. 

Madagascar rubber ranks higher in price than most other 
African sorts. Considering the greater loss sustained in washing, 
it costs nearly as much at times as fine Para. It is a favorite with 
manufacturers of hard rubber, on account of the fine lustrous 



22 GRADES OF CRUDE RUBBER. 

polish which it assumes under the buffing-wheel. The principal 
classification is between "pinky" and "black." 

Pinky comes in round balls, weighing i^ to 4 pounds, black 
on the outside from exposure to the air, but having a pinkish- 
white look when cut. 

Black, also in small balls, when cut shows a dark color, and 
is more or less sandy and dirty. 

Tamatave being the principal seaport, its name is liable to be 
applied to any grades shipped from there. But what is described 
as "Prime pinky Tamatave" is the best rubber produced in Mada- 
gascar. 

Majunga rubber, from the west coast town of that name, is a 
dark rubber of special excellence, ranking next to "pinky" in price. 

Niggers (or negroheads) are designated as "East coast" and 
"West coast," and also as "Red ball," and "Gristly." They gener- 
ally contain sand and dirt. 

Brown cure (or brown slab) is a still lower grade. 

Unripe is the lowest. This term is applied to balls containing 
bark in the center. 

Madagascar rubber is cured ( i ) by the use of salt water, in 
which case the water is never wholly expelled, leading to a heavy 
rate of shrinkage, and (2) by artificial heat. The island is rich 
in rubber forests, but the exports are restricted by the wasteful 
methods of the natives, which exhaust the trees and vines, par- 
ticularly near the coast. 

EAST INDIAN. 

Assam rubber is strong and of firm texture. It is fairly elas- 
tic, though often less so on account of carelessness in gathering 
and the introduction of impurities. There are four grades usually 
(No. I to No. 4), of which the lower ones are extremely dirty and 
contain soft rubber. The better grades when cut have a glossy, 
marbleized appearance, somewhat pinkish in color. Assam rubber 
is marketed in small balls, made by winding up strings of rubber 
dried on the trees, and also in oblong slabs of irregular size, wrap- 
ped in plaited straw. The output has declined for several years, 
the attempts at the cultivation of new trees in Assam having been 
without practical results. Meanwhile the same species has been 



EAST INDIAN RUBBER. 23 

found in Burma, where the production of rubber has grown at an 
equal rate with the falHng off in Assam. 

Rangoon rubber is the product of Burma, exported through 
the port of Rangoon, and differs so little from Assam rubber as 
to require no separate description. Four grades are marketed, at 
practically the same prices as for Assam rubber. 

Java rubber, from the island of this name, is dark and glossy, 
of a deeper tint than the Assam sorts, with occasional red streaks. 
Otherwise, its history and characteristics are nearly identical with 
those of Assam rubber. Three grades are recognized. The milk 
dries on the surface of the trees, on exposure to the air, and the 
shrinkage of the better grades is slight. 

Penang rubber (from one of the states in the Malaysian penin- 
sula, including the island of Penang) is also very similar to that 
from Assam. There are three or four grades, at slightly lower 
prices than the Assam sorts bring. 

Borneo rubber ranks below the other Asiatic sorts, being 
lower in price, with a higher rate of shrinkage. It is of a whitish 
color, changing with age to a dull pink or red. It comes to market 
shaped like pieces of liver, and is soft, porous, or spongy. The 
pores are filled with salt water or whey, for the reason that salt 
is used to coagulate the rubber, and the water evaporating leaves 
a saline incrustation in the cells. There are three grades, the first 
of which is a good rubber, while the lowest, when cut, is almost 
as soft as putty, and is worth little. 

Gutta-susu is a local name applied in Borneo to what is 
known in the markets as "Borneo No. 3." 

Ceylon scrap is the product of a few small plantations in 
Ceylon of the South American tree known as "Ceara rubber." 



CHAPTER II. 

SOME LITTLE KNOWN RUBBERS AND BASTARD OR PSEUDO GUMS. 

For the last fifteen or twenty years reports have come in from 
all over the tropical world regarding the discovery of gums, some 
of which were similar to India-rubber, while others were more like 
Gutta-percha. In a few instances these gums have appeared on 
the market in due time under various names and have been use- 
ful. This is not the rule, however, and it is due to a variety of 
reasons. The first, perhaps, is the scientific attitude of those who 
primarily examine the samples received at the great centers of 
civilization. Unless gums are of high grade, and bear promise of 
being nearly as valuable as a good grade of India-rubber or Gut- 
ta-percha, they' are usually pronounced as worthless, or nearly so. 
These same experts, it is well to remember, condemned reclaimed 
rubber and substitutes, which may lead the manufacturer to sus- 
pect that his wants are not always appreciated by the learned. It 
is possible, of course, that the scientists and experts are right, and 
that it would have been better had reclaimed rubber or substitutes 
never been known. Nevertheless, rubber manufacturers are ever 
in the market for them, and would welcome many of the pseudo 
gums and find large uses for them, if once they were within reach. 

Aside from the scientific attitude is the indififerent attitude of 
the gatherers in their native wilds, and of the importers who see 
little profit in such cheap gums, and of the manufacturers them- 
selves, who wait until a neighbor has tried something new before 
venturing to experiment. 

It is only sufficient to recall what is needed in rubber com- 
pounding to see how many of these gums could be made valuable. 
For example, sometimes simple stickiness is called for ; in another 
case only insulating qualities and stickiness ; in still another, wa- 
terproofing qualities and stickiness; and it is well to add here, 
that where only one valuable quality exists in a gum others can 
often be supplied. As a matter of fact, in the present state of 
compounding and manipulation, the presence of resins is not 
heeded, short life can be overcome, and intractability can be done 
away with. 

24 



SOME LITTLE KNOWN RUBBERS. 25 

A few years ago a leading American rubber manufacturer ^ 
attempted to secure from Mexico a quantity of the bark from a 
small tree which was believed to yield rubber, with a view to ex- 
tracting the gum, by the boiling process. His agent, not under- 
standing the instructions given, had enough of the shrubs cut off 
at the ground to make a steamer load, and shipped them entire — 
wood and all. A liberal yield was obtained of a gum equal in 
quality to a good grade of Centrals. The undertaking did not 
prove profitable enough, however, to cause it to be repeated. But 
without doubt it would pay to engage in the extraction of rubber 
from this shrub in the district where it abounds. More recently y 
the writer has received a sample of gum, worth perhaps 35 cents 
per pound at present prices, which was the product of another 
Mexican shrub, said to be found in great quantities, and needing 
only harvesting and pressing to produce a valuable rubber. 

It is with the hope that some of the gums mentioned in the 
following pages may be brought before the rubber manufacturers 
the world over, that space has been given to them. 

SOME LITTLE KNOWN RUBBERS. 

Jeve Rubber. — Known only by hearsay. Probably the pro- 
duct of the Siphocampylos Jamesonianus, found in the valley of 
the Mayo, in Colombia, and also in Ecuador, and described by 
Humboldt. 

Cow Tree Rubber. — The cow tree is very plentiful in tropi- 
cal South America and yields a milk commonly used for food. 
This milk contains considerable caoutchouc, which is about 30 per 
cent, resin. Botanically it is known as the Brosimum galactoden- 
dron. [Dr. D. Morris, "Cantor Lectures," 1898.] 

Baka Gum. — Found in the Fiji archipelago. Comes from 
Ficus ohligua (Foret). Used by natives for birdlime. Sap very 
abundant. Gum little known. Samples sent to England were 
reported upon as being suitable for mixing. As prices are to-day 

would be worth about 50 cents a pound. [Kew Annual Report, 1877.] 

CuMAi Rubber. — From the milk of a tree found on the Rio 
Negro and Uaupes, in Brazil. None comes to market. This milk 
is used by the natives for waterproofing purposes. 

[Dr. D. Morris, "Cantor Lectures," 1898.] 



26 SOME LITTLE KNOWN RUBBERS. 

MusA Rubber. — A gum expressed from the peel and leaves 
of the banana and pisang plants. No gum yet on the market. Pro- 
cess patented in England by Otto Zurcher, of Kingston, Jamaica. 
Also called "Banana Rubber.^^ 

Mandarnva Rubber. — A low grade of South American gum, 

somewhat like Ceara rubber. Little known. Is said to grow on 

the dry arid uplands of the interior. Is one of a number of gums 

that bear the native names, Cauchin, Pau, and Massaranduba. 

[Revue Coloniale (Paris) — "Report on the State of Sao Paulo."] 

Abba Rubber. — This is an African rubber, from Lagos. It 
probably is the product of the Ficus Vogelii. It is low grade rub- 
ber and cures soft and short. There is a large percentage of resin 
in the milk. t^^- ^- Morris, "Cantor Lectures," 1898.] 

Manga-ice Rubber. — Argentine republic. It is very abun- 
dant. Produces good rubber. 

[E. L. Baker, Consul at Buenos Ayres, U. S. Consular Reports, 1892.] 

Maboa Gum. — Said to be produced from a species of Ficus 

in Santiago de Cuba. 

[Consul Reimer, United States Consular Reports, 1892.] 

DuRANGO Rubber. — Said to be produced from a plant of the 
genus Cynanchum, belonging to the natural order Asclepiadeae, 
found in the Mexican state of Durango. A specimen was exhi- 
bited at the Philadelphia Centennial Exhibition in 1876. Probably 
identical with a rubber of which a sample was sent to the writer 
from Mexico in 1896. Very black, sticky, and full of vegetable 

matter. Would rank with a fair Accra flake. 

[Henry H. Rusby, M. D.] 

Brazilian Birdlime. — The sap of the Artocarpus incisa is 

used by the Brazilians for birdlime and glue. When coagulated 

and dried the gum is white and somewhat similar to Gutta-percha. 

At ordinary temperatures it is hard and brittle, but with a little 

heat becomes plastic, and at the temperature of boiling water is 

soft and very sticky. It is soluble in bisulphide of carbon, and 

insoluble in alcohol and water. A similar gum of a chocolate 

brown color comes from the Urostigma Gamelleira. 

[R. H. Biffen, Botanical Laboratory, Cambridge.] 

Beira Rubber. — Another name for stick rubber, gathered on 

the east coast of Africa, and shipped from Beira. 

Root Rubber. — A rubber obtained from the roots of a semi- 



BASTARD OR PSEUDO GUMS. 27 

herbaceous plant known as the Carpodinus sanceolatus. Very 
abundant in the open grassy country of the Congo Free State. 

[Dr. D. Morris, "Cantor Lectures," 1898.] 
Amazonian Resin Rubbers. — The valley of the Amazon 
contains many trees and plants that are caoutchouc producers, but 
which are generally neglected, as the gatherers are seeking the 
more valuable Hevea. Among these are mentioned the trees 
known under the native names of Amapa, Sucuba, Surva, Taman- 
guiro, Molango, etc. All of these show a marked percentage of 
resin in the milk. [Torres.] 

BASTARD OR PSEUDO GUMS. 

Balata is the gum of the "bully" or "bullet" tree, found in 
British and Dutch Guiana, and in Venezuela. The Venezuelan 
product is known as "block" Balata; that from the Guianas as 
"sheet." Balata also differs in color, the white being considered 
better than the reddish. In character this gum occupies a position 
between India-rubber and Gutta-percha, combining in a degree the 
elasticity of one with the ductility of the other, and freely softening 
and becoming plastic and easily molded in hot water. The milk, 
diluted with water, is said to be drunk by the natives as a substitute 
for cow^s milk. Balata is dried ordinarily by evaporation. A more 
rapid coagulation is effected by the use of spirits of wine. Alum 
and sulphate of aluminum are sometimes used to coagulate, but 
are not very satisfactory. The gum is sometimes mixed during 
the gathering with the milk that produces gum known as Touch- 
pong and Barta-Balli. Balata shrinks in washing from 25 to 
50 per cent. It is used principally in the manufacture of belting 
and for insulation w^ork. It has been utilized also for golf balls 
and as a substitute for India-rubber in dress shields. 

Pontianak is a cheap inelastic gum imported from a town 
of the same name in Borneo. "Jelutong" is the import name in 
the United States, besides which the names "Fluvia" and "Gam- 
bria" have also been applied to it. The gum is used for a friction 
and filler. It is whitish in color, looking something like marsh- 
mallow candy, smells strongly of petroleum, and oxidizes readily 
on exposure to the air. It is believed to be the product of the 

tree known as the Dyera costula. 

[Consul R. Wildman, United States Consular Reports, 1892.] 



28 BASTARD OR PSEUDO GUMS. 

TuNO is a trade name of uncertain origin applied to a gum 
gathered principally in Nicaragua and Honduras. It is the pro- 
duct of what has been called the "sterile rubber tree" and also the 
"male rubber tree" of Nicaragua. The milk is coagulated with 
the aid of heat. The gum is but slightly elastic, is very sticky 
when heated, and is cheap. It is used as a friction gum, and is 
also mixed with Balata in the manufacture of belting. Sometimes 
is is sold under the name "Seiba gum," its identity being lost by 
ingenious massing and manipulation under water. Nicaragua 
rubber adulterated with ''Tuno" in coagulation soon hardens and 
loses its elasticity. Also spelled "Toonu^' and "Tunu." 

Almeidina. — This comes from West Africa, particularly 
from the Cameroons and Angola, and has been found in the Solo- 
mon Islands. It is obtained from the tuber-like roots of a tree 
or shrub, and comes to market in small and sulphur-colored 
nodules, resembling potatoes, for which reason it has been called 
"potato gum." When broken open these balls look like putty, 
and although quite brittle when cold, the gum easily softens in 
warm water and may be drawn out in threads, which are possessed 
of some elasticity. It is completely melted at 240° F., and 
remains rather sticky after melting. It almost completely dissolves 
in cold benzine ; in fact, nearly all of the solvents ordinarily used 
in rubber manufacture dissolve it. It mixes and dissolves with 
rubber in almost any proportion and up to 25 per cent, at least. 
Not only does it not injure the rubber, but is said to be beneficial 
to it. In working on the mill a pungent vapor arises from the 
mass, which, however, has no poisonous effect. In using this gum, 
a little caustic soda sometimes is added to the water when it is 
being washed; other manufacturers add tannic acid. Animal or 
vegetable fixed oils do not dissolve Almeidina, and, therefore when 
mixed with it are apt to rot it. Mixed with Gutta-percha this gum 
is practically indestructible. The name "Almeidina" is that of the 
first important shipper of the gum ; in England the spelling "Alma- 
dina" has come into use. The gum is known also as "Euphorbia 
Q-\xm." [Thomas Christy and W. Lascelles-Scott.] 

Gum Chicle. — A gummy resinous substance found around 
the seeds of the Achras sapota, a tree growing abundantly in the 
warm damp regions of Mexico and "also in portions of Central 



BASTARD OR PSEUD O GUMS. 29 

America. Chicle should be of a whitish color, odorous, and free 
from impurities, but often is adulterated with an inferior pink or 
reddish soil. It is solid and brittle at ordinary temperatures, but 
becomes plastic when placed in hot water. It is quite soft at 
49° C. (120° F.). It is used chiefly in the United States 
in the manufacture of chewing gums, and to a small extent 
in England for adhesive plasters. It has been used for modeling 
purposes and for mixture with India-rubber for insulation work. 

Cativo Gum. — This comes from the sap of the mangrove 
called "Cativo" in the United States of Colombia. The gum is 
fluid at 130° F., and if the temperature is raised to 212° F. 
it is easily filtered and impurities removed, and a somewhat objec- 
tionable smell greatly lessened. The gum is then of a clear red- 
dish brown color. It mixes easily with rubber and is said to pro- 
duce a very tough compound. [Spon's Encyclopedia.] 

ToucHPONG Gum. — This is without doubt a rubber gum, 
entirely distinct from Balata. The rubber dries in strips on the 
trees, and what little of it comes to market has not been recognized 
as a distinct sort. Samples sent to England, however, have been 
favorably reported on. It is found throughout the Guianas. Prob- 
ably from Sapkiin higlandulosufn. Spelled "Touchpong" by Jen- 
man ; "Touchpong^^ by Morris ; "Pouckpong" by Dr. Hugo Miller. 

[Dr. D. Morris, "Cantor Lectures," 1898.] 

Abyssinian Gutta. — An adhesive acid gum of an earthy 
brown color, similar to common gutta in external appearance. 
Softens in water, but keeps a very great elasticity. On drying 
it remains exceedingly adhesive, therefore could not be used in 
place of Gutta-percha, but with proper treatment would undoubt- 
edly make an excellent friction gum. 

[Supplied by Mr. Thomas Christy.] 

Yellow Gutta. — This comes from the Sunda Isles, from the 
genus Payena. It is practically a compound of India-rubber with 
two resins. One of these is crystalizable and the other is pitchy. 
If the raw material is treated with boiling alcohol the resins are 
taken off and the remaining product appears to be good India- 
rubber. [Edouard Heckel and Fr. Schlagdenhauffen, 1888.] 

Gutta Grek. — A gum that comes from Palembang, in 
Straits Settlements. It appears very much like India-rubber, but 



30 BASTARD OR PSEUDO GUMS. 

is permanently softened and destroyed by heat sufficient to melt 
it. It smells like Gutta-percha rather than India-rubber. 

[T. Bolas in Colonial and Indian Exhibition Reports, 1887.] 

GuTTA Bassia. — Found between Upper Senegal and the Nile. 
Has the appearance and apparently many of the properties of Gut- 
ta-percha. Softens in warm water and becomes glutinous at the 
boiling point. Is soluble in sulphide of carbon, chloroform, ben- 
zole, and alcohol. Can be kneaded in water as easily as ordinary 
gutta. [Heckel and Schlagdenhauffen.] 

Gutta-Shea. — Said to be the nearest approach to Gutta- 
percha among African products ; obtained from the "Shea,'^ "Ga- 
1am," or "Bambouk" butter-tree (Butyrospermum Parkii.) The 
butter is the solid fat contained in the seeds and is used in making 
hard soaps. Gutta-shea is separated from the fat in the course 
of the soap making and is found to be present to the extent of 
from 5 to 75 per cent. A kind of Gutta-percha is also obtained 
from the trunk of the tree in small quantities. Also known as 

"Karite gum." [G. F. Scott Elliott, M. a., F. L. S., Botanist.] 

Gutta Terap. — ^A substance closely allied to both Gutta- 
percha and India-rubber; used in Singapore in the manufacture 
of birdlime; is made from the juice of the Artocarpus Kunstleri. 
Also known as "Gutta-trap." 

[Dr. D. Morris, "Cantor Lectures," 1898.] 

Gutta Horfoot. — This is a vegetable juice sent in sealed 
tins from the Straits Settlements, which yields a material like 
India-rubber of fair quality. No way of coagulating the juice, 
where it is gathered, seems to be known. 

[T. Bolas in Colonial and Indian Exhibition Reports, 1887.] 

Talotalo Gum. — Found in the Fiji archipelago. Comes 
from Tabernoemontana Thursioni (Baker.) The gum is hard, 

gutta like, and without elasticity. [Kew Annual Report, 1877.] 

Cattimandu Gum. — This is one of the Euphorbium gums, 
the natives using the milk as a cement to fasten knives in their 
handles. Under the influence of heat it becomes soft and viscid 
and when dry is very brittle. It is probably about as useful as 
Indian gutta. Found in Vizagapatam, India. [Hon. w. Elliott.] 

TiRUCALLi Gum. — This is a Euphorbium gum, from the In- 
dian plant known as milk hedge. The milk of this plant is used 



BASTARD OR PSEUDO GUMS. 31 

for various purposes, chiefly medicinal, in India, and has been sug- 
gested as a substitute for Gutta-percha. Like Gum Euphorbium, 
it has a very acrid character, and the collection of it is a very dan- 
gerous operation to the eyes. When dry it becomes very brittle, 
but when warmed in water is quite plastic. 

[India-Rubber Journal, Sept. 2, 1885.] 
CooRONGiTE. — Sometimes known as Australian Caoutchouc. 

An India-rubber-like material, discovered many years ago near 

Salt creek, a short distance from the coast of South Australia. It 

was first observed in little hollows of sand and resembled patches 

of dried leather, but it generally occurred in the swamps. It is 

supposed to be of the petroleum series. Other scientific authorities 

in England and America ascribe to it a vegetable origin and regard 

the gum as exuding from a plant or lichen. 

[India-Rubber Journal, Sept. 2, 1885.] 

Pala Gum. — Found in Assam and Ceylon. The wood and 
the bark are valued in India for their medicinal qualities. The 
tree yields an abundant milky juice, which after coagulation acts 
something like Gutta-percha. It readily softens in hot water and 
takes impressions, which are retained when cold. Also known as 
"Indian Gutta-percha." Comes from the Dichopsis elliptica. It 
has been used as an adulterant of Singapore gutta for some years. 
It was used also as birdlime or cement and keeps well under water. 
Is hard and brittle when cold. The resin or crystalban is easily 
removed by boiling alcohol and the residue appears to be a very 
fair gutta. [Kew Bulletin, 1892.] 

GoA GuM.^Discovered by Senbor Da Costa. It is a gum 
that comes from the mival-cantem, which grows wild in the Cou- 
can district, and is also planted for hedges. Chocolate in color, 
softens under heat, is easily molded, and thoroughly waterproof. 

Macwarrieballi Gum. — Arubber gathered inBritish Guiana 

from the Forsteronia gracilis. From the report of the director 

of the Kew gardens, to whom a sample was submitted, it would 

seem that, while the gum is at present unfit for use in place of 

ordinary caoutchouc, because of its stickiness, it might be of value 

in cements, frictions, and the like. 

[G. S. Jenman, Botanic Gardens, Georgetown, 1888.] 

Cape Cattamandu. — Derived from an Euphorbia found at 

the Cape of Good Hope. The juice is so acrid as to give intense 



32 BASTARD OR PSEUD GUMS. 

irritation to any part of the body with which it may come in con- 
tact. The gum has been used as an anti-fouling dressing for ship's 
bottoms, but is little known otherwise. 

Mangegatu Gum. — This comes from Vizagapatam and is a 
gum of the bastard gutta type, similar to gutta trap, and is said 
to come from the Ficus Indica. 

MuDAR Gum. — This comes from an Asclepias, commonly 
known as gigantic swallow wort (Calotropis giganteus.) The 
shrub is found throughout the southern provinces of India and 
grows to a height of from six to ten feet. Produces a gutta-like 
substance, which becomes plastic in hot water, and in other ways 
acts somewhat like Gutta-percha. It insulates badly, but is recom- 
mended for waterproofing. 

[Dr. Eugene Obach, "Cantor Lectures," 1898.] 

Barta-Balli. — One of the best known native trees in the 

Guianas. The milk of this tree has usually been mixed with Balata 
milk and is said to give it its reddish tint. The gum when dried 
by evaporation is rather sticky and soft, but when precipitated in 
alcohol is dry and firm. Reports from England are rather con- 
demnatory as the gum is said to absorb a great deal of water in 
washing, which it retains very obstinately. The same rubber, 
dried by precipitation by spirits of wine, is said to be very brittle. 
Known also as Cumaka-balli. [G. s. Jenman.] 

Sarua Rubber. — Found in the Fiji archipelago, from Alsfo- 
nia plumosa (Labill.) Formerly collected largely, now but little 
comes to market. Natives take no interest in its collection. Is 
soft at first, but hardens after a time and becomes inelastic. Is 
about the color and consistency of putty. Natives collect juice 
in three months and it coagulates almost at once. Comes from 
stems and leaves. No juice in trunk of tree. 

[Kew Annual Report, 1877.] 

JiNTAWAN. — A bastard Gutta-percha — perhaps Pontianak — 
mentioned by Thomas Hancock in four patents and also by Taylor 
and Duncan. 

Zapotine. — A name for a solution made from Gum Chicle 
dissolved in alcohol which is treated in the following manner: 
According to one process, Zapotine is exposed to carbolic acid gas, 
or to compounds containing carbon, for vulcanization. In an- 
other, in which it was claimed that it was converted into a vul- 



BASTARD OR PSEUDO GUMS. 33 

canite, the Chicle solution was combined with white lead and sul- 
phur, and vulcanized. 

Mule Gum. — Another name for Ceara rubber. 

Susu-POKO (meaning English tree milk). — A gum from a 
tree growing in the Malay peninsula, used in the place of Gutta- 
percha, after being cleansed and treated with chloride of sulphur. 
Mentioned by Leonard Wray in 1858. 

Talaing Rubber. — Analmost black rubber which, when cut in- 
to, is white and porous presenting a honeycombed appearance, the 
cavities being filled with a watery fluid. It is quite tough and elastic, 
and appears to be of good quality. It comes from a creeper which 
is abundant in the Philippines, in Malacca, and Indo-China. The 
juice is very abundant, and is coagulated by being boiled in water. 
LM. H. Pierre, formerly director of Saigon Botanical Gardens.] 

Canoe Gums. — From the bark of the breadfruit tree, which 
is found so plentifully in the islands of the Indian archipelago, 
comes a thick mucilageous fluid which hardens by exposure to 
the air. When boiled with cocoanut oil it makes a tough rubber- 
like substance wholly waterproof, and very lasting. It is used or- 
dinarily for waterproofing seams of canoes, pails, etc. It is also 
used, when fresh, as a birdlime. 

/PicKEUM Gum. — A shrub that is said to be very plentiful in 
Central America and Mexico, produces a gum fully equal to Afri- 
can flake. The gum is gathered by cutting the shrubs and expres- 
sing the juice. A machine for this purpose is all that is needed to 
add another valuable rubber to the products of the countries named. 

Neen Rubber. — A rubber-like gum said to be produced by 
an insect, reported from Yucatan. The insect belongs to the Coc- 
cus family, feeds on the mango tree, and swarms in those regions. 
It is of considerable size, yellowish brown in color, and emits a 
peculiar oily odor. The body of the insect contains a large pro- 
portion of grease, which is highly prized by the natives for its 
medicinal properties in skin diseases. When exposed to great 
heat, the lighter oils of the grease volatilize, leaving a tough wax 
which resembles shellac. When burnt this wax produces a thick 
semi-fluid mass, like a solution of India-rubber. 

Sieba Gum. — -See Tuno. 

Jelatong. — See Pontianak. 

Fluvia. — See Pontianak. 



CHAPTER III. 

I.— DIVISIONS IN RUBBER MANUFACTURE AND PRIMARY PROCESSES IN 
MANIPULATING THE GUM. 

The foremost European manufacturers of rubber goods, as 
a rule, make everything in the line of compounded rubber, hard 
or soft, and in addition often are large producers of Gutta-percha 
goods. In the United States, on the other hand, the tendency has 
been to specialize the industry and as a result it has divided itself 
naturally into the following general lines: Mechanical rubber 
goods ; Pneumatic and solid tires ; Molded work ; Druggists', sur- 
gical, and stationers' sundries ; Dental and stamp rubbers ; Surface 
clothing; Carriage cloth; Mackintoshes and proofing; Boots and 
shoes ; Insulated wire ; Hard rubber ; Cements ; Notions ; Plasters ; 
and Reclaimed rubber. 

The following brief description of the manipulation of rubber 
in these various lines is given simply because there are superin- 
tendents and managers who are experts in one line, say for exam- 
ple, of Druggists' sundries, but who may be wholly unfamiliar 
with even the machinery used in other lines. 

Mechanical Rubber Goods. — This line of rubber manufac- 
ture, which is also known in Europe as technical rubber goods, 
embraces all the heavier combinations of India-rubber, metal, and 
fabric which are used in engineering and industrial lines. It 
covers, for example, belting, packings, hose, and special articles 
of almost endless variety and description. 

This portion of the rubber business has always been the pio- 
neer in the production of new compounds, new processes, and 
better and heavier machinery. Its manufacturers always have 
welcomed new grades of rubber, have been the first to utilize those 
that were a drug on the market, because of lack of knowledge as to 
their manipulation, were familiar with the uses of reclaimed rub- 
ber while yet other lines were simply considering its use, and with 
hundreds of compounds and cures, with a broad knowledge of 
industrial achievement in all lines, they have often pointed the way 
for manufacturers in other lines to follow, to the betterment of 
their goods or their pockets. 

34 



BOOTS AND SHOES. 35 

The mechanical rubber goods factory has, to begin with, the 
same outfit in the way of machines for manipulating the crude 
gum as have the other lines. Their mixing mills, however, are 
often heavier, and their calenders run at higher speeds, while they 
have in addition enormously heavy hydraulic belt presses, huge 
vulcanizers, and scores of special machines designed for indi- 
vidual problems required for their line of work alone, or perhaps 
for a single factory alone. The kind of vulcanization used in this 
work is (i) open steam heat, where the goods are buried in 
French talc or wrapped in fabric; or (2) dry heat, where they are 
confined by molds, and held in a steam press during the cure; or 
(3) where the goods, as in the case of belts, are molded between 
the platens of the press itself, while curing. Even in this line of 
work there are some concerns that only do special parts of it. 
For example, there are certain large factories that make only cer- 
tain types of packings, which have a worldwide sale, and on which 
they are run continuously. Many of these mills also are large 
producers of tires. 

Boots and Shoes. — The manufacture of rubber boots and 
shoes, although apparently a simple business, not only requires 
large capital but is one that has often been overtaken by disaster. 
It is a matter of common knowledge that, given the same com- 
pounds, the same machinery, and the same skilled workmen, no 
two mills are able to turn out exactly the same grades of goods. 
Quality is one ingredient that may or may not be added to the 
goods, no matter how honest the endeavor. That there are rea- 
sons for this, no one can doubt, and that the day will come when 
this branch of manufacture will be an exact science is probably 
true. That, however, will entail a definite knowledge of rubber 
from the moment it first sees the light as a creamy sap exuding 
from the tree, through every event in its life — in coagulation, 
transit, storage, factory manipulation, compounding, calendering, 
curing, its death in the service of man, and its later resurrection 
in the process of reclaiming. 

Nor is this all. There will be a need for exact information 
regarding the ingredients added in the course of compounding, 
their relation one to another, mechanically and chemically, so long 
as they be joined together. This, coupled with atmospheric and 



36 DIVISIONS OF THE MANUFACTURE. 

climatic conditions, not to say a profound knowledge of the errors 
and accidents due to the ignorance, prejudice, or carelessness of 
the ordinary workman, constitute so complex a problem that suc- 
cessful manufacturers to-day feel fairly safe in frankly stating 
to would-be competitors that they have no need to hide their for- 
mulas, as they are but a small part of the problem. 

In the complete rubber shoe plant there are found, for initial 
equipment, washing rolls, mixers, refining mills, and calenders 
such as most of the other lines employ. In addition, there are 
special calenders, with engraved rolls for shoe-upper work ; others, 
also, with engraved rolls for soleing; presses for molding boot 
heels, sole-cutting machines, and, of course, vulcanizers. As this 
class of goods is cured by what is known as the "dry heat" — that 
is, by being confined in dry hot air for several hours — it will 
readily be seen that it is radically different business from mechan- 
ical rubber goods, for instance. These dry heaters are simply 
large air-tight rooms, fitted with steam pipes for heating, lined 
with tin, double walled to prevent radiation, into which hundreds 
of pairs of boots or shoes are run on skeleton cars, to undergo the 
process of vulcanization. The manufacture of rubber footwear 
in brief, therefore, consists in washing, drying, compounding and 
calendering the rubber, the cutting of the calendered sheets into 
various shapes for cementing over lasts in the shapes desired, the 
varnishing, and the dry heat cure. 

To-day the ingredients used in this compounding are almost 
identical in all of the American mills. In Europe, however, there 
is a wider difference, and it would not be surprising if rubber shoe 
compounding experienced the same revolution that other lines 
have known, now that the price of crude rubber has gone so high. 
The last great changes in shoe compounding, which came between 
1878 and 1882, were radical and of value to both manufacturer 
and consumer. That the present compounds are perfect, or that 
the ingredients used are the best, no one can affirm. Besides, as 
all other lines have progressed, is it not now the turn of the boot 
and shoe trade? 

Druggists', Surgical, and Stationers' Sundries. — This 
part of the rubber business entails more skilful manipulation and 
more finesse in manufacture than almost any other line. An atom- 



DRUGGISTS' SUNDRIES. 37 

izer bulb, for example, must be graceful in shape, with delicately 
smooth surface, of good color, and either of the non-blooming 
variety or so near it that the sulphurous efflorescence will be so 
slight as to pass unnoticed, while in mechanical goods a length of 
garden hose may be of any color, may bloom until crusted with 
sulphur crystals, but if it "stands up to work," it is the best, and 
is beautiful in the eyes of the trade. 

The question of colored rubber is one that has interested this 
branch of the business from its inception. In none other is so 
much white rubber made and, incidentally, none others get such 
good effects. This insistence by customers for white goods and 
by physicians for black containing no trace of lead has entailed a 
deal of trouble upon this trade, for the manufacturers until re- 
cently could not go into the open market and buy a high grade 
of white recovered rubber, while of black there is ever an ample 
supply, and in black goods to suit the physician he is forced to 
substitute a dry bulky vegetable black for oxide of lead or white 
lead, and then not get so good a result. 

The machinery used is very similar to the equipment of a 
mechanical goods factory, but the scale is smaller. Washers, 
grinders, calenders, tubing machines, steam vulcanizers, and small 
steam presses are the machines used. Naturally special machines 
are employed in certain parts of the work, but their use is limited 
to a few factories and to comparatively insignificant specialties. 

The feature in this trade which stands out most distinctly 
from other rubber lines is perhaps the manufacture of hollow 
work, as atomizers, syringes, breast-pumps, and a host of other 
balls and bulbs. The parts for these are cut from sheets of com- 
pounded rubber, cemented together at the edges, inflated to the 
general shape of the mold and cured in an open steam heat. In 
order that the ball may perfectly fill the mold during the cure, a 
few drops of water or a little ammonia are put inside of it which, 
swelling under the heat, develops pressure enough to perfectly 
shape it and add to its outer surface the finish found on the inner 
surface of the mold. 

The difficulties that manufacturers in this line experience in 
making perfect goods are legion, as they are in other lines. They 
are added to by the fact that the trade, as already indicated, de- 



38 DIVISIONS OF THE MANUFACTURE. 

mand articles of beauty from a gum that was designed for utility 
solely. A trace of black in a white compound may spoil hundreds 
of dollars worth of goods, nor can such trace be rubbed oflf, 
scoured out, or eradicated, after vulcanization. Hence, the whites, 
blacks, reds, and other colors must be mixed in separate mills, and 
the trimmings and scraps kept sedulously apart. 

Pure gum — that is, rubber compounded only by sulphur or 
some other vulcanizing agent — is also largely produced in this 
line. For example many make what is known as dental dam, the 
pure sheet used by dentists. This is generally a sulphur com- 
pound cured in open steam. Certain manufacturers, however, 
practice the vapor cure with good success in making these goods. 
This cure gives a beautiful finish, but if it is not done with great 
skill it is disastrous to both the workman and the goods. 

Dental dam, surgical bandages, and stationers' bands repre- 
sent the highest priced and least compounded goods, while stop- 
ples, erasive rubber, and common tubing represent the other ex- 
treme. Between the two is a latitude that allows of a variety of 
combinations and compounds that no man can number. 

Clothing, Carriage Cloth, Mackintoshes, and Proofing. 
— This business may be handled, in a measure, as the mechanical 
goods business is; that is, the gums mixed by heat on ordinary 
mixers, and then spread by calenders on the fabrics which give the 
articles their strength. This is the manner in which rubber sur- 
face clothing is run. The machinery is simple, since, in clothing, 
the parts are cemented together and cured in dry heat. In car- 
riage cloths, after calendering, the goods are grained on embos- 
sing rolls, varnished, and run into a dry heat. 

The Mackintosh and proofing business, however, is some- 
what a departure from this. Here the gum, after mixing dry, is 
usually put in churns with a cheap solvent, and reduced to a solu- 
tion. It is then applied to the cloth with a knife spreader. 

For double-texture work, a simple doubling machine brings 
two surfaces together. A portion of the business that has divided 
itself from the rest, is what is known as proofing for the trade. 
Here manufacturers simply coat the cloth and sell it to others, who 
make it up into garments, or anything in fabric or rubber for 
which there may be a call. The mackintosh manufacturer to-day 



PNEUMATIC TIRES. 39 

not only is familiar with a great variety of rubber gums and ingre- 
dients used in compounding, but is also an expert in fabrics, as his 
business is really closely akin to the tailoring business. 

Pneumatic Tires. — Although the tire business seemed at 
first to be a natural part of the mechanical rubber goods business, 
it really proved itself, later, to be a business wholly distinct from 
it. Even the large manufacturers of mechanical goods who began 
tire making on a considerable scale, keep this part of their business 
distinct from other branches as a rule, running it as an entirely 
separate department. Aside from this, large concerns have sprung 
up that manufacture nothing but tires, and although some of these 
use their scrap and refuse in the manufacture of certain mechan- 
ical goods, they do not all find it profitable. 

The general machinery used in making tires is the same that 
is used in the work of preparing rubber in the other lines. There 
are two general classes of tires manufactured, however : those that 
are molded, and those that are made in such a way that they can 
be wrapped for the process of vulcanization. Wrapped goods, 
of course, are cured preferably in an open heat. In the one case 
the tires are cured in presses, sometimes in nests of molds, and 
sometimes in vulcanizers. Molded tires are cured under pressure, 
exactly as the atomizer bulb is in the druggists' sundries line. 
Various ingenious and valuable processes in special machines have 
been invented, and are now in use in this industry. A minor in- 
dustry that has grown up in connection with the tire business, 
and that has increased the practical knowledge of the uses of rub- 
ber wonderfully, is that of tire repairing. 

A part of the tire business that is of great interest is the mak- 
ing of the solid or cushion molded tire used on vehicles. A very 
large business is done in this, the work being a simple process of 
mixing the prepared compound, forcing it into shape through a 
tubing machine, and molding in an open steam heat. A tire now 
coming into use that is going to develop a very large business is 
the big pneumatic tire used on various types of automobiles. The 
knowledge gained through the manufacture of pneumatic bicycle 
tires, which, by the way, was one of the hardest problems that the 
rubber trade ever solved, has proved wonderfully effective in de- 
veloping the skill necessary to make this heavier and more impor- 



40 DIVISIONS OF THE MANUFACTURE. 

tant article. This tire, like the bicycle tire, is built up of frictioned 
duck, with an outer coating of high-grade rubber carefully vul- 
canized. While a variety of compounds undoubtedly will be used 
in its manufacture, it is hardly possible that any manufacturer will 
be able to sell a very low grade of goods. In other words, the life 
of the tire is so important, and the purchaser so anxious for a good 
article, that adulteration or cheapening to any great extent is not 
a present danger. 

Insulated Wire. — The manufacture of insulated wire, either 
with India-rubber or Gutta-percha insulation, is a line that is 
more distinctly apart from other portions of the rubber business 
than almost any other. For Gutta-percha, the general machinery 
used is described in the chapter on that gum. Where India-rub- 
ber is used, the crude gum is treated in the same way as in me- 
chanical goods. It may be forced over the wires by tubing 
machines, or welded together in strips that are run between 
grooved rolls. 

Braiding machines are also a part of the outfit for weaving 
the protective covering, and the wire is usually wound on huge 
drums and vulcanized in open steam heat. Polishing machines, 
testing machines, and various mechanical contrivances are, also, 
a part of this equipment. The line of compounds used is one 
adapted almost wholly to this industry, and embraces a great va- 
riety of ingredients and gums that afe treateid specifically under 
their special heads, elsewhere in this book. 

Mold Work. — A part of the rubber business that belongs 
either to the mechanical or the druggists' sundries line has, during 
the past few years, detached itself from the rest, so that to-day 
many large factories are run simply in producing small mold work. 
They have the usual equipment of rubber machinery, special appli- 
ances for filling and emptying molds, and the usual aggregation 
of hard and soft metal molds that run into thousands of dollars 
in a short time. The extent to which this business is carried may 
be imagined when it is known that one company runs 80 presses 
on this work, and many have from 20 to 50 in constant service. 
When it is remembered that very rarely are two compounds 
exactly alike, it will be seen that, in this line also, the expert com- 
pounder has a wide field for thought and experiment. 



HARD RUBBER AND CEMENTS. 41 

Hard Rubber. — In spite of the hundreds of substitutes for 
vulcanite, or hard rubber, that have been produced, the demand 
has in no way fallen off, and these mills are running full to-day 
on the production of this semi-metal. The old fashioned com- 
pound, consisting of 2 pounds of India-rubber to i pound of sul- 
phur, is still in use in certain goods. Modern progress and chem- 
ical knowledge have, however, added a great many compounds 
for specific uses, so that almost any degree of quality or hardness 
or price is now furnished on call. 

The business, primarily, is a simple one, the hard rubber 
machinery being like that used in other lines. In the manipula- 
tion of the gum for vulcanization, and in its finish, however, 
special machines are necessary. The finishing machines are lathes, 
saws, buffers, etc., somewhat similar to what might be used for 
turning hard wood. The mechanical factories often do a little 
in hard rubber in the line of valves, and the druggists' sundries 
mills often make their own syringe fittings, but the bulk of the 
business in America is done by mills that make only vulcanite 
the year around. 

Cements. — Many rubber factories are run wholly on this 
line of work, the gums being mixed as in a general rubber busi- 
ness, put into solution in churns, and sold by the barrel for an 
infinite variety of purposes. Hundreds of different formulas are 
in use for cements sold for general and specific purposes. The 
leather shoe business, for instance, calls for a dozen or more special 
cements. The bicycle business has need for a great many grades 
of what are known as tire cements and what are known as punc- 
ture fluids. The latter, however, do not really belong to the 
cement business. Stickiness, waterproof qualities, durability, and 
cheapness in their goods are sought by all cement manufacturers, 
and, in order to secure these qualities, skill is demanded in com- 
pounding in no way inferior to that shown in other lines of rub- 
ber work. 

Dental and Stamp Rubber. — The manufacture of unvul- 
canized gums for the use of dentists and rubber stamp manufac- 
turers is an industry apart from other lines, and one that has 
assumed quite large proportions. The rubber is compounded and 
sold by the manufacturer, and cured and finished by the dentist 



42 DIVISIONS OF THE MANUFACTURE. 

or rubber stamp manufacturer. In stamp work the rubber is com- 
pounded for soft rubber and many hundreds of tons are sold dur- 
ing the year, while of course the dental rubber is so mixed that 
under the cure it becomes vulcanite of the color desired. The 
machinery for this work consists chiefly of washers, mixers, and 
calenders. 

Notions. — A department of the rubber business little known 
is that which takes in such work as waterproof dress bindings, 
dress shields, childrens' aprons, diapers, etc. Several large facto- 
ries manufacture these goods, mixing their rubber by the usual 
dry process, coating it on calenders, and having special machines 
for forming and curing the goods in their special shapes. In the 
manufacture of dress shields, the vapor cure is often practiced 
very successfully. The rubber manufacturers of this class are not 
by any means inexpert compounders. They have also, perhaps, 
gone as far as any in deodorizing rubber goods, so that the smell 
of the gum or any compounding ingredients is wholly done away 
with. 

Plasters. — There are few factories that keep wholly to this 
line of work. It is perhaps as simple as any part of the rubber 
business, a fair grade of rubber being washed, dried, and mixed 
by the usual methods, and calendered upon the fabric that forms 
the base of the plaster. These goods are not vulcanized, of course. 
Though a variety of gums and medicaments is used in this com- 
pounding, the range is probably smaller than any other line of 
rubber manufacture. 

Reclaimed Rubber. — In the United States nearly a dozen 
mills are employed in the reclaiming of waste rubber, such as old 
boots and shoes, hose, tires, etc. In this business are used crackers, 
sheeting mills like ordinary grinders, and, indeed, general ma- 
chinery not dissimilar to that used in a mill where crude rubber 
is compounded. They have in addition, however, lead lined tanks 
for acid treatment, vulcanizers or, better, devuicanizers, huge vats 
for washing, magnets for removing metal, sieves, and the like. 
This branch of the rubber business is not supposed to be deeply 
interested in compounding, in spite of the fact that it is sometimes 
suggested that earthy matters and heavy adulterants do find a use 
in reclaiming mills. 



WASHING AND MIXING. 43 

il.— THE WASHING, MIXING, AND CALENDERING OF RUBBER. 

The primary process that rubber undergoes when it enters 
a rubber mill after weighing, is washing. As a rule this is done 
with clear water. At the same time, certain acids, alkalies, and 
foreign substances that are contained in the rubber are not easily 
soluble in water, and yet may be easily removed. The first thing 
to do, therefore, is to know what is to be expected in various 
grades of rubber. Perhaps there is no better way to get a bird's 
eye view of what the washer might wish to remove from the gum 
than by briefly cataloguing the different substances used by the 
natives in coagulating the juice. 

There is no question but that the differences between varying 
grades of rubber, besides being due to a somewhat different chem- 
ical composition, are also due in a measure to varying methods 
of collection and coagulation of the sap. It is undoubtedly true 
that no one method of collection would be best for all kinds of 
rubber gathered, even if it were possible. At the same time, it 
is of interest to the practical rubber manufacturer to know pretty 
nearly what systems are pursued, and particularly what ingre- 
dients are added to the sap, to produce coagulation, as the presence 
of certain residues may affect his compounds. 

Smoking rubber is the system with which the world at large 
is most familar, and is practised in the Amazonian forests in the 
collection of Para gum. Several kinds of palm nuts are used to 
produce a thick smudge, but those ordinarily used are from the 
Urucuri palm (Attalea excelsa.) This smoke has been found by 
analysis to consist mainly of acetic acid and creosote, the latter 
being a well known preservative of rubber. Fine Para rubber is 
nearly always smoked in this way. Coarse Para is air dried. 
Ceara rubber is also, to a certain extent, smoked in the gathering, 
the palm nut used being that of the Eucturbe edulus. There is 
also a kind of gum tree found in the forests of the Isthmus, and 
where it is impossible to get palm nuts, its wood is used for the 
coagulating smoke. 

AcHETE Juice. — A native process for coagulating the sap of 
the rubber tree, which prevails throughout Central America, in- 
volves the use of an alkaline decoction made from the juice of a 



44 DIVISIONS OF THE MANUFACTURE. 

plant called "achete" or "codiSso" ( I pomoea hona-nox, Linn., and 
also Calonyction speciosum). This is combined with rubber milk 
in the proportion of i pint to i| gallons of the latter. During 
coagulation the vessels are often heated from 165° to 175° F. 
After coagulation, the rubber is dried for twelve or fourteen days. 
The kinds of rubber coagulated in this fashion are Mexican, Nic- 
araguan, and in fact almost all of the rubbers that come under the 
head of Centrals and are obtained from the Castilloa elastica. 

Sulphur Fumes. — According to James Collins, rubber of 
the Para varieties is sometimes exposed to the action of the fumes 
of melted sulphur, which affects coagulation. This process, how- 
ever, is very rarely followed. 

CoYUNTLA Juice. — This is an astringent juice made from 
the Mexican weed of that name. When the rubber milk is 
gathered, it is placed in earthenware vessels and whipped with 
the weed, which causes coagulation. The Mexican rubber known 
as Tuxpam is treated in this way. 

Machacon Juice.— Cartagena rubber, which is gathered 
carelessly, is coagulated in a hole in the ground by the addition of 
the juice of the root of the "machacon" — a strongly alkaline 
solution. 

NiPA Salt. — A salt obtained by the burning of the plant 
known as the Nipa fructicans. Is used in the coagulation of 
Borneo rubber. 

Lime Juice. — Lagos rubber and some other African sorts 
are coagulated by the addition of a little lime juice, which is added 
as the sap flows from the vine. 

Alum. — This is used all through the Isthmus of Panama, in 
coagulating Accra rubbers, and other African sorts. Pernam- 
buco rubber is also treated with a water solution of alum, as is 
the Nicaraguan at times. 

Salt. — Many kinds of low-grade rubber are coagulated by 
the addition of salt or brine. Borneo, for instance, is coagulated 
in that way. Madagascar rubber receives a treatment of salt- 
water. Mangabeira rubber is treated with a mixture consisting 
of I part of salt to 2 parts of alum. Nicaragua rubber is also 
often coagulated with salt. 

Lime. — A final process in the coagulation of rubber in India 



COAGULATION OF RUBBER. 45 

is the washing over with lime. Collins also mentions the use of 
lime in connection with the coagulation of Para ruber. 

Soap and Wood Ashes. — The medium grade rubbers all 
through Central America are often coagulated by the use of soap, 
and where that is not plenty, of a strong lye from wood-ashes. 

Spirits of Wine. — This is used sometimes in the coagula- 
tion of Balata. 

Torres System. — In addition to the natural methods de- 
scribed above, there are several that give some evidence of an 
intelligent study of the sap and the substances best adapted for 
this work. Under the Torres system a liquid is made by a secret 
formula, from the roots and fruits of certain South American 
palms, which, when added to the sap, preserves it from curdling, 
so that it will keep for weeks. It can thus be transported to a con- 
venient place for smoking. 

Helper Process. — This consists of the addition of a solution 
of acetic acid, and is based on the knowledge derived from the 
analysis of the smoke of the Urucuri nuts. 

Centrifugal System. — Another form of coagulation, that 
has recently been tried with considerable success, is the using of a 
centrifugal machine which removes the watery contents from the 
gum, and produces a marvelously clear elastic rubber. 

Heat, Air, Sunlight. — Various rubbers are coagulated sim- 
ply by the exposure to slight artificial heat, to the sunlight, or 
merely to the air. Such are the coarse Para rubbers, certain of 
the Centrals, African, and East Indian rubbers. Fiji rubber is 
coagulated in the mouths of the natives, and Angola rubber on the 
arms and breasts of the natives. 

The very first manufacturing process in the manipulation of 
rubber of any kind, and for any use, is that of the cleansing. This 
is usually done by passing the gum again and again between cor- 
rugated rolls, while fine streams of water remove the various impu- 
.rities that are exposed by the tearing action of the rolls. These 
impurities are bits of vegetable substances, earth, sand, acids, and 
alkalies. .The old type of washer for removing these was a couple 
of corrugated rolls 6 or 8 inches in diameter, and 12 or 14 inches 
in length. Modern methods, however, have introduced larger 
rolls, until to-day one machine, when it is the highest type of three- 



46 DIVISIONS OF THE MANUFACTURE, 

roll washer, will cleanse enough gum to keep a huge factory busy. 
Some rubbers are so full of sand that it is almost impossible 
to remove it wholly. For this purpose is used a tub with a false 
bottom made of fine wire, and also with a stirrer. The thimbles, 
for instance, after being run through the washer, are put in the 
tub without any attempt at sheeting, and stirred until a large por- 
tion of the sand is removed. 

Another type of washer is one that is quite similar to a paper 
engine; in fact, paper engines are often used in rubber washing. 
The special value of this type is that the rubber in its movement 
about the tub is floated more or less, and the sand and earthy 
matters sink to the bottom, while the bark and vegetable matters 
can be seen and easily removed. 

Certain manufacturers, following Austin G. Day's ideas, have 
used alkaline solutions in washing certain gums, to neutralize the 
vegetable acids, and it is a question if it might not be as well to use 
dilute acids to neutralize the strongly alkaline qualities of gums 
that go through certain kinds of coagulation. Some factories also 
examine the coarser grades of gums chemically, and give them a 
treatment to remove odor. As a rule, however, manufacturers 
rush them through the washing machines, sheet and dry them, and 
get them into the mixing mills as soon as possible. 

The drying of rubber, according to earlier practice, required 
a great deal of time. It was the boast of more than one rubber 
mill that no Para rubber was used by them until it had been dried 
for a year. The manufacturers of mechanical rubber goods were 
the first to break away from this tradition. In many cases they 
found, when there were rush orders on hand, that they must put 
on their mills gum that was practically just oflF the washer, 
and mix it, or else lose orders. Of course, they were forced to 
get most of the moisture out, or neutralize what was left, and they 
learned incidentally that they got a stronger compound with the 
green gum than with the "seasoned," whence the belief grew up 
that the months and years of drying was not necessary, as had 
before been supposed. In addition to this, some of them learned 
that long drying meant oxidation on the outside, or the turning 
of rubber into resin, which further increased their doubt of the 
wisdom of the slow drying process. 



DRYING AND MIXING. 47 

These thoughts once entertained, it was not long before vari- 
ous plans were introduced into the drying, for hastening the re- 
moval of the moisture. The simplest of these, of course, was 
artificial heat, and the presence of a fan for removing the moisture 
laden atmosphere. Later developments have brought about a pro- 
cess for drying rubber very cheaply at quite a high heat, lasting 
only a few hours, that gives it to the man who runs the mixer, 
hot from the dryer, and that wholly does away with the expensive 
process of breaking down. This latter idea, is to some, of course, 
as revolutionary as was the first thought of quick drying, but that 
it is wholly in the line of progress, is proved by the fact that it 
has been used for a number of years in one large factory whose 
goods stand very high. 

The milling of crude rubber is simply putting the dry rubber 
which is found in a tough, intractable sheet, on hot rolls, and run- 
ning it until it gets to be a softened homogeneous mass. The 
gum, when this is accomplished, is ready for mixing. These mix- 
ing rolls are run at different speeds and are called friction rolls, 
and the various adulterants and ingredients that are to be incor- 
porated with the rubber are pressed into a softened gum by their 
revolution. 

No general rule can be laid down for mixing in all lines. An 
expert compounder knows that certain gums should be mixed on 
cool rolls, and others under considerable heat. His knowledge 
of specific compounds teaches him to hasten mixing in many cases 
where another, without skill, would require very much more time 
to get the same result. In some cases one ingredient is put in with 
the others, in some, it is necessary to put it in last. Some have 
dissolved substances that would make the rubber stick to the rolls 
like glue unless they are put in at just the right time ; others have 
so large a proportion of earthy matters that, unless the gum is 
humored, it apparently will not take them in, and so on. Each 
line of work and, in fact, each factory has its own special methods, 
and often one or more skilled mixers who can handle compounds 
that none of the others seem to be able to do anything with. 

The use of the calender is simply to sheet the goods so that 
they may be easily made into the desired forms. The simplest 
form of calender is a mixing mill with the key that normally holds 



48 DIVISIONS OF THE MANUFACTURE. 

one roll in place withdrawn, so that both run by even motion, 
which is used in many small factories where nothing but molded 
work is made. 

The modern sheeting calender is ordinarily a three-roll ma- 
chine. It is sometimes made with four rolls, however, and these 
rolls may be almost any size, the widest for rubber work being 
little less than 80 inches. No little skill is required for running 
the calender on a variety of stocks, nor can any general rules be 
laid down for calender work. This is proved by the value that is 
set upon good calender men, and by the difference that there is 
between the work of a good one and a poor one. There are as 
many different kinds of calenders as there are patterns of mixing 
mills. A sheet calender has smooth rolls, and is for running 
absolutely smooth goods. In shoe work there are engraved rolls, 
pebbled rolls, and soleing calenders engraved in the likeness of the 
shoe sole. The carriage drill business has embossing calenders, 
and so on. A type of calender that is useful in most lines of work 
is known as the friction calender, the rolls in which, run at uneven 
speeds, drive the gum deply into the fabric. 

Where India-rubber is handled in solution there is used in 
place of the calender a spreading machine, known under various 
names of "Yankee flyer," "English spreader,^^ "Doughing ma- 
chine,'' etc. In this a sheet of rubber is spread on the cloth by 
being placed on an endless apron of the fabric, the apron running 
over the roll against which hangs a heavy knife. A very thin 
coating of the rubber solution is constantly scraped off this sur- 
face, which then passes over hot drums or steam chests, evaporat- 
ing the solvent. 



CHAPTER IV. 

VULCANIZING INGREDIENTS AND PROCESSES. 

While Charles Goodyear's patents for the vulcanization of 
India-rubber by the use of sulphur and heat were in force, a mar- 
velous amount of ingenuity was shown in the attempts to accom- 
plish the same results by the substitution of other ingredients for 
sulphur, either with or without the use of heat. These experi- 
ments and inventions embrace vulcanization, by means of chlo- 
rides, nitrates, nitrites, fluorides, bromides, iodides, and phospho- 
rets of about all of the common earths and metals, and also many 
gases such as sulphurous acid gas. The majority of these experi- 
ments have been lost sight of, partly because the Goodyear pro- 
cess is now open to the world, and partly because, for the majority 
of goods, the sulphur and heat cure is not only the cheapest, but 
the easiest to accomplish. It may be well, however, to review and 
record the experiments in this line, as there is no doubt that for 
special lines in rubber manufacture many of them have a great 
suggestive value to-day. 

One of the very first ingredients to which inventors and ex- 
perimenters turned their attention was zinc. The veteran rubber 
manufacturer, the late Jonathan Trotter, described a process for 
preparing a vulcanizing material which he called hyposulphite of 
zinc. It was made from a solution of caustic potash saturated 
with flowers of sulphur and then treated with sulphurous acid gas. 
This solution he mixed with a saturated solution of nitrate of zinc, 
forming the precipitate that he desired. He used 3 pounds of 
hyposulphite, to 10 pounds of rubber, curing from 3 to 5 hours, 
at 260° to 280° F. 

Another American, E. E. Marcy, some years later patented a 
compound of hyposulphite of zinc and rubber which is apparently 
almost identical with Trotter's discovery, although he disclaimed 
similarity, and also made public the process in which he used a 
combination of hyposulphite of zinc and sulphide of zinc, the com- 
pound being 2 pounds of rubber, i pound sulphide of zinc, i pound 
hyposulphite of zinc, and other ingredients as deemed necessary. 
These goods were of a beautiful white color, were said not to 

49 



50 VULCANIZING INGREDIENTS. 

bloom, and did not need the sunning process then in use. At the 
same time they depended upon sulphur and heat for whatever 
vulcanizing was accomplished. 

Another attempt to get a good substitute for sulphur was in 
the production of what is known as sulphite or hyposulphite of 
lead. James Thomas describes at length a compound in which he 
mixes hyposulphite of lead and artificial sulphide of lead in equal 
proportions, his compound being for vulcanization, 2 parts by 
weight of India-rubber and i part of the vulcanizing material. 

Following this thought, came E. E. Marcy again, who mixed 
sulphide of lead and carbonate of lead in the proportions of 2 
parts of sulphide of lead, i part carbonate of lead, and 2 parts 
protoxide of lead in place of the carbonate. 

Then Oscar Falke and Albert C. Richards brought out a 
compound consisting of 6 parts India-rubber, 2 parts sulphide of 
antimony, and ^ part sulphite of soda, curing at 270° to 280° F. 

A. K. Eaton, in no uncertain terms, disclaimed vulcanization 
by the use of free sulphur, but claimed to be the first to use sul- 
phide of manganese. He also gave a formula for making it, which 
was by mixing intimately 44 parts of peroxide of manganese with 
32 parts of sulphur, and exposing the mixture to heat in a covered 
crucible. He vulcanized several hours, from 250° to 310° F. 

George Dieffenbach claimed sulphite of alumina as an ingre- 
dient which, in connection with heat, would bring about vulcani- 
zation. He used this in a compound for a dental rubber, which 
had for its basis India-rubber, amber, linseed oil, sulphide of cad- 
mium, oxide of tin, vermilion, and pulverized feldspar. 

Charles T. Harris cured India-rubber by combining it with 
an artificial sulphide of bismuth, which he explained as being the 
artificial tersulphide, or polysulphide of bismuth. He describes 
this as being a heavy black powder, and the compound which he 
advised for soft rubber was 100 parts India-rubber, 75 parts car- 
bonate of lead, and I2|^ parts polysulphide of bismuth, cured in 
a dry heat at 245° F. for i^ hours. 

The veteran Henry W. Joselyn discovered that shale — an 
earth that is very plentiful in New Jersey — combined by heat 
with sulphur, formed a sulphide which could be used in curing 
rubber, and hastened to patent it. 



EARLY INVENTORS. 51 

Andreas Willman, with more originality, brought out a pro- 
cess for combining India-rubber with "anhydrous chlorides, sul- 
phates of alkalies" and powdered coke or coal, and claimed that 
his best result came from chloride of ammonium and coke. His 
compound was made up of litharge, lampblack, and powdered 
coke, in connection with from 2 to 10 per cent, of his vulcanizing 
mixture. 

Edwin L. Simpson formed a vulcanizing compound by mix- 
ing benzoin gum with pulverized sulphur, and boiling it in linseed 
oil. It was used in a dry heat, the compound being i pound of 
India-rubber, 2 ounces vulcanizing compound, 8 ounces litharge, 
and 8 ounces whiting. 

J. A. Newbrough manufactured a vulcanizing material which 
he called acid resin, made of turpentine and sulphuric acid. This 
he incorporated in India-rubber in the proportion of 6 ounces of 
acid resin, to i pound of India-rubber, and cured at 300° to 320° F. 

The use of selenium as a curing agent was discovered by E. 
E. Marcy, while connected with Horace H. Day, then prominent 
as a rubber manufacturer. He advised the use of equal parts of 
India-rubber and powdered selenium, and, to produce a glossy 
finish, he added selenium carbonate and whiting. 

At the same time there were many other inventors who were 
experimenting with processes that were somewhat in the line of 
the well-known Parkes cold-curing process. For example, it is 
a matter of history that the late Joseph Banigan, early in his career 
as a rubber manufacturer, cured wringer rolls by an acid process. 

Dubois C. Parmelee invented a process which he called "her- 
mizing," to distinguish it from curing or vulcanizing, instead of 
the Parkes process, in which the solution of chloride of sulphur 
and bisulphide of carbon were used. He recommended briefly a 
solution made as follows : 10 pounds of coal-tar naphtha, in which 
was dissolved i pound of sulphur. Into this solution he passed 
dry chlorine gas until it assumed a fine yellowish-green color. 
This solution he used as a dip for such goods as would be cured by 
the acid treatment. Parmelee also claimed the discovery of a 
solution made of coal-tar naphtha, bisulphide of carbon, and a 
solution of sulphur in bromine, mixed with this. 

H. A. Ayling patented a cold curing process in which carbon 



52 VULCANIZING INGREDIENTS. 

spirits, one of the petroleum series, was mixed with chloride of 
sulphur, instead of the usual bisulphide of carbon. 

Referring again to the suggestions of chlorine in the work- 
ing of rubber, R. F. H. Havermann reduced India-rubber to a 
solution and subjected it to the action of chlorine. He also, in a 
later patent, described the washing of the chlorine out of the rub- 
ber with alcohol, and the addition of ammonia and lime, the result 
being, according to his specifications, a white hard rubber. 

Working in the same line, John Helm, Jr., dissolved India- 
rubber in benzine and mixed it with liquid chlorine in the propor- 
tion of 12 ounces of chlorine to i pound of gum. His claim was 
that he could get rubber of any color and of any degree of hard- 
ness by this process. 

In the line of hard rubber manipulation and vulcanization, 
Mr. Meyer (connected with the India-Rubber Comb Co.) patented 
a process for curing vulcanite in a vessel wholly or partly filled 
with water, the water in which the rubber was contained being in 
a tight receptacle, and the heat being raised above 300° F., the 
pressure of the surrounding steam keeping it from vulcanizing. 
This obviated the danger of burning, and was of great value in 
the production of certain goods. 

While these and other inventors were trying to cure rubber 
without sulphur, and without interference with the Goodyear 
patents, certain others were at work on other gums. For example, 
John Rider, who was at the head of a Gutta-percha company, pro- 
duced what he called mettallothyanized Gutta-percha. In this, he 
first heated the Gutta-percha, then mixed 3 pounds of hyposul- 
phite of lead and zinc with 8 pounds of gum, and sometimes added 
also a little Paris white, or magnesia. He then put the compound 
from 2 to 10 hours in a dry heat and cured it at 280° to 320° F. 

John Murphy changed this compound somewhat, by advising 
the incorporation of sulphur in the proportion of 2 to 6 ounces of 
sulphur, to 10 pounds of Gutta-percha. This sulphur, by the way. 
obviated the preliminary heating of the Gutta-percha, which was 
supposed to volatilize the ingredients that had before rendered it 
unvulcanizable. 

A curious process for the manufacture of hard rubber was also 
brought out by William Mullee. In this, just as soon as the rubber 



PARKES'S PROCESS. 53 

was washed, the sheets were immersed in the sulphur bath, heated 
to 220° F. The water and other impurities in the rubber were said 
to be extracted by the action of the heated sulphur. After boiling 
30 minutes, the sheets were removed with tongs and washed to 
prevent crystalization. They were then subjected to the same pro- 
cess a second time. The rubber was then compounded in the old 
fashioned way, on rolls, the proportions being 17 to 24 ounces of 
sulphur to 16 ounces of rubber. The claim for this was, that the 
compound when cured was tougher than any others ever known. 

William Elmer prepared what he called "elastic selenide of 
caoutchouc.^^ He first dissolved the India-rubber in bisulphide of 
carbon, placed it under pressure, and heated gradually. When 
brought to about 300° F., the liquified selenium was put into the 
apparatus drop by drop, the solution in the meantime being kept in 
constant motion. This elastic selenide he claimed to be semi- 
fluid which, when evaporated, possessed all the characteristics of 
India-rubber. 

The Parkes cold-curing process is so widely known as to 
require but a word. It is based on the invention of Alexander 
Parkes, and depends upon the faculty that chloride of sulphur has 
for vulcanizing India-rubber. (See Chloride of Sulphur.) 

A curious process, similar to that of Parkes, is Caulbry's pro- 
cess, by which it is claimed rubber can be vulcanized at ordinary 
temperatures, by using an intimate mixture of chloride of sul- 
phur and dry chloride of lime. During this mixture, and when 
the smell of the chloride of sulphur will be noticed, the tempera- 
ture of the mixture will rise, the mass becoming plastic by the 
softening of the sulphur. If a mixture of this kind, in which sul- 
phur is in great excess, is added to the solution of India-rubber in 
bisulphide of carbon, the rubber will be vulcanized at an ordinary 
temperature, or perhaps with a slight warming. Chloride of sul- 
phur used pure is too corrosive in its effect on India-rubber ; it is 
therefore reduced in all cases. Only thin articles can be vulcan- 
ized in this way. 

A recent patent taken out in England by Edmond Gamier 
relates to the vulcanization of India-rubber by the use of alum. 
Alum processes for curing in the past have not been very success- 
ful. This patent, however, has some novel features. It calls for 



54 VULCANIZING INGREDIENTS. 

particularly dry alum treated with a solution of terebinth of ben- 
zol and shellac, or some similar gum. In use he takes 8 ounces of 
alum and a solution composed of i part gum and 20 parts benzol. 
He mixes together the ingredients that are usually employed in 
the manufacture of rubber, specifying 3 pounds of whiting, i 
pound barytes, 8 ounces lime, i^ pounds oxidized oil, and 8 ounces 
of India-rubber. When these have been thoroughly mixed to- 
gether and specially treated, alum is incorporated with them and 
well compounded, being passed through the mixing rollers cold. 
It is then calendered. 

Amorphous Sulphur. — The fusing of i pound of sulphur 
with 4 ounces of Canada balsam produces what is known as amor- 
phous sulphur, which is said to cure rubber so that it will have no 
tendency to bloom. The preparation has a very pungent sulphur- 
ous odor. Patented by Dr. F. Wilhoft, of New York. 

Artificial Sulphuret of Lead. — There are several combi- 
nations of lead and sulphur which may be produced artificially. 
That one containing the most sulphur has a composition of 13 per 
cent, of sulphur and 86 per cent, of lead. Its specific gravity is 
about 9.4. In color it is black. It melts at a strong red heat. The 
other sulphur compounds of lead have much less sulphur, one con- 
taining but 9 per cent, and the other only 4 per cent. What is 
known as hypo-sulphite of lead is a mechanical mixture of the 
above first named, with a suitable percentage of sulphur to effect 
vulcanization. It is also known in the rubber trade as "Eureka 
compound" and "Burnt hypo." These compounds when pure — 
that is, when free from adulteration — are of great value. They 
produce goods that are jet black and have little odor and are free 
from bloom. They are reckoned as the safest vulcanizing agents, 
as it is almost impossible to burn goods that depend upon their 
presence for cure. They are used in either dry or wet heats. 

Barium Sulphide is prepared from heavy spar by making a 
dough of it with charcoal and oil and subjecting it to a white 
heat. Sulphides of the alkaline metals, potassium, sodium, cal- 
cium, and barium, will vulcanize rubber, whence the term "alka- 
lised rubber." 

Bromine. — A heavy deep red volatile liquid, possessing a 
most peculiar and unpleasant odor, and giving off vapors most 



CHLORIDE OF SULPHUR. 55 

irritating to the air passages and lungs. It's very name means 
stench. It has a powerful action upon most organic bodies, color- 
ing animal matter brown, while it bleaches coloring matters, dyes, 
etc. Its specific gravity is 3.18. A piece of sheet rubber dipped 
into bromine is vulcanized instantly. It is somewhat soluble in 
alcohol, and very soluble in ether, bisulphide of carbon, chloro- 
form, etc. Messrs. Newbrough and Fagan filed two patents in the 
United States for the use of bromine in vulcanization, both with 
and without iodine. By adding to iodine ^ its weight of bromine, 
proto-bromide of iodine is formed, which is said to combine with 
India-rubber and produce a hard compound on being exposed i 
hour to a temperature of 250° F. To prevent the forming of an 
explosive the iodine and bromine were separately treated with oil 
of turpentine to which had been added a quarter of its weight of 
sulphuric acid. It was then mixed with the gum in the proportion 
of 2 pounds 1 1 ounces to every pound of gum. Bromine was also 
used alone by these inventors, the material after molding being 
plunged into the liquid, and left there long enough to harden. To 
prevent the hardening of the material, while in the bath, chloro- 
form or any other solvent of rubber was added in the proportion of 
I part to 9 parts of bromine; in other words, the rubber vulcan- 
ized in the air after its withdrawal from the liquid. 

Chloride of Sulphur. — Sulphur and chlorine form three 
compounds, the monochloride, the dichloride, and a tetrachloride 
of sulphur. The substance usually used in the arts is the first 
named or a mixture of the first two. It is an oily liquid of the 
specific gravity 1.7, and boiling at 239° F. It has a pungent 
smell and decomposes on contact with water or watery vapor. 
Pure chloride of sulphur is of an orange yellow color of great 
density. It fumes strongly when exposed to air, throws off the 
vapors of hydrochlorine, and is quite poisonous, severely attacking 
the mucous membranes. It is widely known as the active agent 
in Parkes's cold-curing process, where it is used in connection with 
bisulphide of carbon. A common formula for this is chloride of 
sulphur, I part by weight, bisulphide of carbon, 30 to 40 parts by 
weight ; immerse from 60 to 80 seconds. In the manufacture of 
balloons and toy balls, the solution is a far weaker one. That for 
the outside dip is 10 parts of chloride of sulphur to 100 parts bi- 



56 VULCANIZING INGREDIENTS. 

sulphide of carbon, while for the inside it is i6 parts chloride of 
sulphur to I, GOO parts bisulphide of carbon. When it was com- 
mon to cure proofed cloth by the cold process, it was done by wet- 
ting its surface with a mixture of 5 to 10 parts of chloride of 
sulphur, dissolved in 100 parts of bisulphide of carbon, then run- 
ning the fabric over heated drums to evaporate the mixture. In 
the sulphurization of oils for rubber substitutes chloride of sulphur 
plays a most important part, nearly all of the amber and white 
products being produced by its use. It also has a curious effect 
upon bastard gums, giving some of them temporarily the elas- 
ticity and appearance of high grade rubber. 

Gold Brimstone. — See Sulphur. 

Golden Sulphuret of Antimony. — This is prepared from 
black antimony by boiling it with caustic soda and sulphur for 
some time. The liquid is then clarified by filtration or settling 
and the clear part treated with a dilute acid, preferably muriatic 
or sulphuric. A golden yellow precipitate is formed which should 
be well washed in water, and dried at not too high a temperature 
in a darkish place. The results of this operation well carried out 
are constant and the composition should be : Antimony, 60.4 ; sul- 
phur, 39.6. Golden sulphuret of antimony heated in a tube will 
give ofif sulphur which will deposit on the cool sides of the tube 
away from the flame and the residue will turn black, being indeed 
the black sulphide of antimony. All samples of this compound 
should be tested for free sulphuric acid by shaking up a little of 
the powder in a test tube with cold or hot water, and testing the 
water afterwards with some barium chloride and blue litmus 
paper. A white cloud in the first place and the reddening of the 
paper in the second place indicate the presence of more or less free 
sulphuric acid. Golden sulphuret prepared with muriatic acid will 
not respond to the first test, but will to the second. 

Golden Sulphuret or Antimony Red (penta-sulphide) is 
used more largely than any other form of antimony in rubber 
work. It is frequently adulterated, sometimes with carbonate of 
lime, oxide of iron, or oxide of antimony, all of which tend to 
harden the rubber. Also called Orange Sulphide of Antimony. 
Properly used, this ingredient produces some of the best effects 
found in vulcanized rubber, in color, texture, and durability. It 



IODINE. 57 

should never be mixed on a very hot mill, should be sheeted and 
placed in cooling racks if it is not to go right to the calender, and 
should be cured in as low a heat as possible. The ideal result will 
be of a golden yellow color, with a very slight bloom, if any. It 
is used only in high cost goods. 

Honeycomb Sulphur. — A vulcanizing compound made by 
boiling a pound of sulphur, and two ounces of benzoin gum to- 
gether, I pound of this material being mixed with a quart of boiled 
linseed oil. 

Hypo-Sulphite of Lead. — See Artificial Sulphuret of Lead. 

Iodine is manufactured from seaweed and is a black-gray 
substance occurring in small shining scales. Its specific gravity is 
4.94 and it fuses at 239° F., giving off violet vapors. It is readily 
soluble in alcohol, benzol, chloroform, and sulphide of car- 
bon. In addition to the formula given under the head of bromine, 
Messrs, Newbrough and Fagan patented the combination of iodine 
and sulphur. In this the sulphur was boiled in turpentine, and 
the oil decomposed and deposited with the sulphur at the bottom 
of the vessel was used in the operation, after being washed in 
dilute sulphuric acid, and dried. The iodine was treated in the 
same manner to prevent explosions. Equal proportions of the two 
were melted together and incorporated in the proportions of 2 
ounces 5 drams, to i pound of rubber. After shaping, the articles 
were put in a vulcanizer and during the first fifteen minutes ex- 
posed to a dry heat, gradually increasing to 320° F., remaining 
there 5 minutes, then dropping rapidly to 250° F., and continu- 
ing for an hour. 

Liquid Chlorine. — Chlorine is a greenish yellow gas at all 
ordinary temperatures. It has strong bleaching properties and 
also a very bad smell and action upon the respiratory passages. 
Ubder a pressure of 127 pounds to the square inch at 60° F., 
chlorine condenses to a yellow liquid, having the specific gravity 
of 1.33. This liquid, however, is unknown in the arts. It is prob- 
able that either a solution of the gas in water or as sulphuric 
chloride in bisulphide of carbon is meant. It has been contended 
that chloride, especially in the last-named solution, is the really 
active agent in curing caoutchouc. Chlorine cannot, as a rule, de- 
stroy mineral colors or blacks produced by carbon. Helm claimed 



58 VULCANIZING INGREDIENTS. 

jthat he was able to produce white hard rubber by incorporating 
chlorine with the mass. 

Liver of Sulphur. — This is really penta-sulphide of potas- 
sium, and is obtained by mixing carbonate of potassium together 
with sulphur. It is called Liver of Sulphur on account of its 
brown color. As it is quite volatile it should be kept in well closed 
glass vessels. The fluid for vulcanizing purposes is a concentrated 
solution of the penta-sulphide, about 25° Baume being right for 
use. To cure with it the liquid is brought to the boiling point in 
a porcelain vessel, the articles to be vulcanized being immersed 
in it. This is known as Gerard's process and is said to be inex- 
pensive and perfectly safe. 

Milk of Sulphur. — Another name for what is ordinarily 
termed precipitated sulphur. It is fine, light, and grayish white 
in color, but is often adulterated with sulphate of lime. It should 
be kept in a dry place, as it has an affinity for moisture. 

Penta-Sulphide or Antimony. — The chemical name for 
Golden Sulphuret of Antimony (which see.) 

Proto-Chloride of Sulphur. — See Chloride of Sulphur. 

Sulphide of Lead. — Occurs native as galena and is one of 
the ores of lead, having a specific gravity of 7.2 to y.y. Com- 
mercially it is found as a black powder, of specific gravity 6.9. 
Its composition is 86.6 per cent, of lead and 36.4 per cent, of sul- 
phur. Sulphide of Lead is a very useful black pigment, and one 
that is used quite largely in rubber works, as it is a good filler and 
assists in vulcanization. It is often made from pure white lead 
by very simple treatment. It materially assists the resiliency of 
Para compounds. 

Sulphur Lotum. — A name for sublimed sulphur that has 
been washed to move sulphurous acids, and carefully dried. 

Sulphide of Zinc. — Sulphur forms with zinc two sulphides. 
One of these, the mono-sulphide, corresponds to zinc blende, 
which, as found native, is of various colors, from yellow to black. 
Its specific gravity is from 3.5 to 4.2. The other is a penta-sul- 
phide artificially prepared and occurs in the form of a white pow- 
der. Upon ignition in the absence of air this latter substance loses 
four-fifths of its sulphur, but the temperature at which this takes 
place is too high to render it available as a source of sulphur of 



SULPHUR. 59 

vulcanization in compounding rubber mixtures. With a slight 
addition of sulphur it is used in the production of white goods. 

Sulphur occurs in a number of different forms, and under 
various names as brimstone, flowers or flour of sulphur, roll sul- 
phur, rock sulphur, etc. Its specific gravity is 1.98 to 2.06. It 
melts at 239° F., thickens and becomes orange yellow at 320° F., 
at 428° it is semi-solid and red, and on carrying the heat 
higher it becomes browner and boils at 788° F. Some of the 
sulphur now used commercially is recovered from alkali waste, 
but most of it comes from Sicily, where it is found native. It is 
more generally used in rubber works than any other ingredient, 
and in all proportions from 3 per cent, up to 100 per cent, of the 
weight of the rubber. The ordinary form in which it is found in 
the rubber factory is in a yellow powder, known as flowers of 
sulphur. It has a slight affinity for moisture, and careful manu- 
facturers keep it covered from air to avoid the formation of sul- 
phurous or sulphuric acids. Mixed with certain oils by heat, it 
forms the black sulphur substitutes that are often used in rubber 
compounding. Sulphur in the form of rolled brimstone is pul- 
verized, sifted, and used in the place of flowers of sulphur, in 
France, and is equally good and cheaper. 

Sulphur Balsam. — A solution of sulphur in fixed oils, con- 
sisting of 2 ounces of flowers of sulphur in 8 ounces of linseed oil, 
used in proofing compounds. 

Versuvian White.— a special vulcanizing material manu- 
factured in England, for use in the manufacture of tennis balls 
and other goods. 

VuLCANiNE. — An English vulcanizing preparation, used for 
both steam and dry heat goods. It occurs either as a white or a 
black powder, depending upon the line of goods on which it is to 
be used. 



CHAPTER V. 

FILLERS AND OTHER INGREDIENTS USED IN DRY MIXING IN RUBBER 

COMPOUNDS. 

India-rubber is compounded for two reasons, the first being 
to reduce the cost without destroying the usefulness of the gum, 
the second being to impart to the gum qualities possessed by a 
great variety of mineral, vegetable, and even animal substances. 
Each of the ingredients treated in this chapter has some specific 
use. While their arrangement may seem a little incoherent to the 
chemist, it will be fully appreciated and understood by the rubber 
manufacturer whose habit of mind leads him to reach out into 
any of the kingdoms — animal, vegetable, or mineral — for assis- 
tants in compounding problems. 

Acetate of Lead. — A white sweetish tasting powder soluble 
in water and alcohol. In its crystaline form it contains about 7 
per cent, of water of crystalization, which is easily driven off at a 
temperature of say 80° to 100° F. Its specific gravity is : crystal- 
ized, 2.3; water free, 2.5. It is a product of the half completed 
process of treating pig lead where the old Dutch method of corro- 
sion is employed in making the carbonate. Its use in semi-hard 
composition was patented by both Goodyear and Payen. India- 
rubber dissolved in oil, to which has been added acetate of lead, is 
used to fill the pores of certain leathers so that the "filling'' shall 
not come through. It is also used in certain varnishes in connec- 
tion with Gutta-percha. 

Agalmatolite. — A silicate of aluminum and potassium re- 
sembling soapstone which is soft enough to be carved with a knife. 
It has no advantages over talc, silicate of magnesia, or soapstone 
in rubber use. It appears, however, in some patented compounds, 
but if the potash principle is necessary, it can be easily added to 
the ordinary powdered talc. The largest deposits of this material 
are to be found in China. 

Antimony. — See Golden Sulphuret of Antimony, Black An- 
timony, and Kermes. 

Argillaceous Red Shale. — The shales, clays, and feldspars 
are all very closely allied and pass the one into the other by gradual 

60 



ALUMINA— ARSENIC. 6i 

decay. A shale that has a large amount of clay in it is termed 
Argillaceous, and the substance mentioned in the heading may be 
briefly termed red clay tinctured with oxide of iron. The analysis 
of Argillaceous clay shows: Alumina 39, silica 46, water 13, iron, 
magnesia, and lime 2. It was the basis of a well-known oil resist- 
ing compound that for years baffled imitation. 

Artificial Sulphuret of Lead. — See Burnt Hypo. 

Alumina. — The oxide of aluminum and a chief consituent 
of clay. Its specific gravity is 4.154. Ordinarily speaking it is 
a very inert substance, insoluble, and not readily attacked by acids. 
It is best known in the arts under the forms of kaolin, corundum, 
emery, etc. As obtained chemically it is a fine white glistening 
powder, feeling harsh and dry to the touch. Eaton's formula for 
the use of oxide of aluminum in making a pure white rubber, was 
India-rubber 40 per cent., oxide of aluminum 55 per cent., and 
sulphur 5 per cent. He describes his process for making the pow- 
der, which was by the burning of sulphate of alumina. 

Anhydrite. — The water free mineral form of sulphate of 
lime or gypsum. It has a specific gravity of 2.9, and is formed 
artificially by heating gypsum so as to drive off all its water. It 
is white in color and crystaline in form. Gypsum that has been 
overheated in the preparation of plaster of paris and that has lost 
its ability to "sef ' is pure Anhydrite. It is used as a filler in rub- 
ber compounding instead of whiting or paris white. 

Arsenic. — A white brittle metal, with a specific gravity of 
4.7 or 3.7, according to its form. Also a popular term for the 
oxide of arsenic sometimes called the white arsenic, which is a 
heavy white powder of the specific gravity 3.7. White arsenic is 
slightly soluble in cold water and to the extent of 10 per cent, in 
hot water. There are several coloring matters formed from arse- 
nic, all of which are to be condemned for general use. The most 
familar are paris green, realgar, which is red, and orpiment, 
which is yellow. The white oxide is rarely used in rubber work, 
and is to be avoided, as are the greens, reds, and yellows. The 
green has been used in mechanical rubber goods, but the color 
was not a valuable one. Hancock vulcanized Gutta-percha with 
orpiment, and Forster used it in "mosaic work" for floor cover- 
ings. An anti-fouling composition for ships' bottoms is formed 



62 FILLERS IN DRY MIXING. 

of Gutta-percha, copper, bronze, and arsenic. Another is formed 
of India-rubber 2 pounds, rosin 7 pounds, and arsenic 2 ounces. 

AsBESTic. — The part of the rock remaining after the richer 
veins of asbestos have been extracted. This remainder is a purely 
fibrous material, clearly showing its origin. For mechanical uses 
it is ground fine, and for all sorts of fireproofing purposes is valu- 
able and much cheaper than long fiber asbestos. It is mined at 
\ Danville, Lower Canada. It makes an excellent compounding 
'material for asbestos packings, etc., in connection with rubber. 

Asbestine. — A pure fibrous silicate of magnesia, called also 
mineral pulp. It is mined near Gouverneur, N. Y., where is the 
only deposit at present known where magnesia shows so distinct 
a fiber. It is very largely used in the manufacture of paper, and 
also as an ingredient in rubber. Apparently the pulverized min- 
eral is a very strong white powder, but in actual use it has not 
much more covering quality than whiting. It was at one time 
used largely in the manufacture of rubber shoes, but, aside from 
being inert and a good filler, was probably no better than whiting, 
while it was more costly. It is often used in white goods, in con- 
nection with oxide of zinc to make a light weight compound. It 
is also known as agalite and asbestine pulp. Its composition is: 
Silica 62, magnesia 33, water 4, iron oxide and alumina i. 

Asbestos (Amianthus). — A fibrous silicate of calcium and 
magnesia, also called stone flax, Salamanda's wool (from an old 
belief that it was originally made from the wool of the salaman- 
da), cotton stone, mountain flax, mountain wood, and mountain 
cork. Its specific gravity is 3.02 to 3.1. An analysis of the 2 best 
known varieties shows : 

Canadian. Italian. 

Silica 40.92 40.25 

Magnesia ' 33-21 40.18 

Water of hydration » 12.22 14.02 

Alumina 6.69 2.82 

Protoxide of iron 5-77 -75 

Soda 68 1.37 

Potash, etc 22 .15 

Sulphuric acid traces .31 

The longest fiber is possessed by the Italian, which is some- 
times 3 feet in length. The Canadian ranges from 3 to 6 inches 
in length, but it is finer, more flexible, and more easily separated 



ASBESTOS— BLACK ANTIMONY. 63 

than the Italian. The mineral divides iteslf naturally into 3 
classes: The first, coarse, brittle, very plentiful, and cheap; the 
second, possessing well-defined fibers of a brownish yellow color, 
fragile, and containing many foreign bodies ; the third, with pure 
white silky fibers which can be woven into textiles. A notable use 
to which asbestos has been put in United States is in the produc- 
tion of the packing known as Vulcabeston (which see). Its low 
conductivity of heat renders it particularly useful in steam pack- 
ings, both for cylinder work and for joints, while its incombusti- 
bility has long caused it to be used for fireproof purposes. There 
are fibers formed of serpentine rock which are much used as a 
substitute for genuine asbestos, and answer nearly as well, being, 
however, shorter in fiber and somewhat less durable. Almost all 
large rubber manufacturers produce packings in which there is 
a certain amount of asbestos, often assisted by infusorial earth, 
asbestine, etc. 

Atmoid. — A very light white earthy matter, marketed by an 
English corporation. Analysis proves it to be an almost pure silica 
— quite close, in fact, to infusorial earth. 

Barytes. — ^A heavy white mineral that in commerce takes the 
form of a fine white or gray powder. It is obtained by grinding 
the mineral heavy spar, or by chemical means from baric chloride. 
Its specific gravity is 4.5. It occurs in commerce under the names 
"permanent white" and "blanc fixe." The artificially prepared 
substance is to be preferred to the finely ground mineral, on ac- 
count of its less crystaline form. The commercial article should 
always be examined to determine its freedom from acid impurities. 
Barytes is also called Witherite, which is the carbonate, and Heavy 
Spar, which is the sulphate. Barytes is chiefly used as an adulte- 
rant for white lead and paints. Thus Venice white contains 
equal parts of sulphate of barytes and white lead ; Hamburg white, 
2 parts to 2 parts of white lead ; and Dutch white, 3 parts to i of 
white lead. It is wholly inert when used as an ingredient in rub- 
ber compounding, and increases the resiliency of rubber, and is a 
make- weight. 

Black Antimony. — A black powder obtained by grinding 
stibnite or antimony ore. It is a sulphide of the metal and is met 
with more or less pure, as it is often prepared from a high grade 



64 FILLERS IN DRY MIXING. 

ore. The sulphur contained in it is unavailable for vulcanizing 
purposes, and if used in compounding it is necessary to add a suf- 
ficiency of sulphur to vulcanize. In the purest form black anti- 
mony contains about 28 per cent, of sulphur and 72 per cent, of 
antimony. It is insoluble in water, but is dissolved by muriatic 
acid or by caustic alkalies. From its solution in alkali a fine brown 
red powder may be obtained by treatment with a dilute acid, and 
this powder, known as kermes, has the same chemical composi- 
tion as that mentioned above. Its specific gravity is 4.6. It was 
formerly used sometimes as a filler, as it was believed to give a 
soft effect in molded goods. It has been almost wholly displaced, 
however, by cheaper and better ingredients. 

Black Hypo. — See Hypo-sulphite of Lead. 

Black Lead. — See Plumbago. 

Blue Lead. — Where zinc ores are found in combination with 
galena, or natural sulphide of lead, the two are often smelted to- 
gether with raw coal and slaked lime, producing a fume called 
blue powder, which is sold under the name of Blue Lead. It is 
an excellent filler, but is not as good as sublimed lead, for exam- 
ple, as it does not impart enough resiliency to rubber. Its chief 
merit is its cheapness. A very fine quality of Blue Lead, contain- 
ing considerable lead oxide, is now on the market, but this must 
not be confused with either of the two low grade articles men- 
tioned in these paragraphs. This Blue Lead is of exceeding fine- 
ness, and gives a peculiarly soft finish to the rubber. Used in the 
place of litharge, it materially assists in the cure, and produces a 
fine black. As it has a high specific gravity, it often displaces 
barytes. Blue Lead is also a name given to an artificial aluminous 
substance occurring either as a loose powder or in a concrete form, 
colored blue by means of some kind of blue dye — aniline or log- 
wood — which does not contain lead. 

Bone Ash. — See Phosphate of Lime. 

Boneblack. — See Animal Charcoal. 

BucARAMANGUiNA. — A transparent amber colored, incom- 
bustible material, found near Bucaramanga, Colombia. It is some- 
what similar to asbestos, for which it has been mentioned as a sub- 
stitute in the manufacture of packings. 

Burnt Umber. — An earth containing a large amount of iron 



BURNT UMBER— CHALK. 65 

oxide of a dark brown rust color. As mined it is called raw 
umber, and the product obtained by calcining it is known as Burnt 
Umber. It is a fairly useful filler in compounding, as its action, 
or rather lack of action, upon rubber makes it safe to use. It is 
used in brown packings and, to a certain extent, in maroon goods. 

Calamine. — An ore of the metal zinc, and a carbonate of 
zinc. Ordinary Calamine, which is a silicate of the metal, has a 
specific gravity of 3.6 to 4.4, and is little used in the arts. Noble 
Calamine, or native carbonate of zinc, is a gray or grayish yellow 
to brown powder, according to its priority. Its specific gravity 
is 3.4 to 4.4. Its nature is earthy, and heat has no action upon 
it. A little of it is said to toughen soft compounds. 

Calcium White. — ^Another name for Whiting. 

Calomel. — A white, tasteless, and inodorous powder of spe- 
cific gravity about 7.2. It is permanent in the air, but should be 
kept in the dark, as light blackens it. When pure it may be wholly 
volatilized by heat, but if this cannot be done, then the sample 
tested contains other bodies. Calomel strikes a black color under 
the action of alkalies. It is insoluble in water, alcohol, ether, or 
benzine. It is the basis of a compound for rendering woven hose 
waterproof, the other ingredients being magnesia, black antimony, 
oxide of zinc, tar, sulphur, and India-rubber. Its office is to hasten 
the cure. 

Carbonate of Baryta. — Known also as the mineral wither- 
ite ; has a specific gravity of 4.3. It is a white powder insoluble 
in water and alcohol. (See Barytes.) 

Carbonate of Lead. — See White Lead. 

Carbonate of Lime. — ^Very familiar under the form of lime- 
stone, marble, or chalk. Specific gravity 2.7 and 2.9. (See Whit- 
ing.) 

Carburet of Iron. — A name given to a mixture of graphite 
and oxide of iron. A fine black-brown powder, fairly heavy spe- 
cifically, although variable. It makes a fair filler in compounding 
being inert and strongly coherent. In packings it has been largely 
used and also in compounds for wagon covers and tarpaulins 
before reclaimed rubber came largely into use. It has also been 
used in cements for card clothing. 

Chalk. — A white soft, somewhat gritty substance, consist- 



66 FILLERS IN DRY MIXING. 

ing chiefly of carbonate of lime. It is made up of myriads of very 
small shells of marine animals long extinct. Its nature is earthy ; 
that is to say, it is not easily affected by ordinary bodies. Acids 
disengage carbonic acid gas from it. Its specific gravity is 2.9. 
If heated to a red heat, carbonic acid gas escapes and quicklime is 
left behind. (See Whiting.) 

Charcoal (animal). — Animal charcoal is made from cal- 
cined bones and has the property, in a high degree, of absorbing 
odors. It is often used, therefore, in deodorizing rubber goods, 
and experimentally by chemists for filtering Gutta-percha dis- 
solved in bisulphide of carbon, where a perfectly clear product 
is desired. Its use is advised by Forster in Gutta-percha com- 
pounds, and by Warne, Jaques, and others for making packings to 
stand a high degree of heat. (See Boneblack.) 

Charcoal (vegetable). — This is a popular term for the 
coal produced by the charring of wood. There are many mate- 
rials which are really charcoals, such as animal charcoal just 
quoted, carbon, coke, graphite, and wood charcoal. All of these 
are practically the same in their pure states, being almost wholly 
carbon. Wood charcoal, which is what is meant in rubber com- 
pounding by vegetable charcoal, consists of carbon, hydrogen, 
and oxygen, the last two being in the proportion to form water. 
As it retains the form of the wood from which it is made, it is 
powdered before use. It is black and brittle, insoluble in water, 
infusible, and non-volatile in the most intense heat. It has the 
power of condensing gases and destroying bad smells. Charcoal 
may or may not be a bad conductor of heat and a good conductor 
of electricity, these properties depending upon the wood from 
which it is made. Technically, it is divided into hard wood 
charcoal and soft wood charcoal. Its composition at ordi- 
nary temperatures is about as follows: Carbon 85 per cent., 
water 12 per cent., ash 3 per cent. It is used in rubber 
compounding in certain vulcanite varnishes and in certain insu- 
lated wire compounds. For this latter use, willow charcoal is 
preferable, as it is a decided non-conductor. It has also been used 
in sponge rubber, with the idea that it acts as a preservative in a 
compound which is very likely to be short lived. One curious use 
for it, a possible and valuable one, was in the attempted manufac- 



CHARCOAL— CORK. 67 

ture of cop tubes from Gutta-percha and Charcoal. Macintosh 
also used large quantities of ground charcoal in place of lamp- 
black in some of his compounds. A French substitute for vul- 
canite paints or lacquers is made of 10 pounds of bitumen, 15 parts 
of Charcoal, and a little linseed oil, mixed by heating. 

China Clay. — See Kaolin. 

Com PC. — A name for a composition used in rubber manu- 
facture in the United States years ago, but not in use now. The 
name, however, clings to two compounds sold by an English 
chemical house for use in rubber work. They are of a secret na- 
ture. No. I is used in the manufacture of oil-resisting valves 
and in tubing for chemical factories, in the proportion of 30 
pounds of Compo to 10 pounds of rubber. No. 2 is used for soles 
for tennis shoes and in mechanical goods, in the proportion of 25 
pounds of Compo to 10 pounds of rubber. 

Cornwall Clay. — See Kaolin. 

CoRK_, in granulated or powdered form, has long been a favor- 
ite ingredient in rubber compounding. Not that it is used in any 
such measure as whiting or barytes, but many mills have used it, 
and a few in large proportions. Used in connection with India- 
rubber and Gutta-percha, it has been the subject of some fifty pa- 
tents. Its largest use, perhaps, was in the manufacture of Kamp- 
tulicon, where India-rubber is used as a binding material, and in 
linoleum, where oxidized oils are used in place of rubber. It was 
also used in what was known as leather rubber, in which palm 
oil distillate, a little India-rubber, and a good deal of granulated 
cork were used. At one time it was also compounded with rubber 
and made up into a waterproof felt for hats. It also went into 
compounds to resist heat, into cricket balls, and into golf balls, 
where it was compounded with Gutta-percha and enough metal 
filings added to give the necessary weight. A rubber blanket used 
in special manufacture also had its surface covered with granu- 
lated Cork as an absorbent material. In some cases the Cork was 
charred and roasted to remove what resinous matter might be in 
it, while in others resinous matter was removed by boiling in alco- 
hol. As is generally known, Cork is the bark of the cork oak, a 
native of the south of Europe and north of Africa. The chief sup- 
plies come from Spain and Portugal. Cork is the basis of the 



68 FILLERS IN DRY MIXING. 

fine black known as Spanish black, which is made by burning the 
refuse in close vessels. 

Corundum. — A mineral which is nearly pure alumina, yet 
of great specific gravity, and of exceeding hardness, being inferior, 
in this respect, only to the diamond. Emery (which see), so 
largely used as a polishing substance, is a variety of Corundum. 

DiATOMACEOus Earth. — See Infusorial Earth. 

Electric Facing. — See Farina. 

Emery. — The average composition of Emery may be taken 
as alumina 82, oxide of iron 10, silica 6, lime i^. Its specific 
gravity is about 3.8 to 4. It is prepared by breaking the stone 
at first into lumps about the size of a hen's egg, then running it 
through stamps, and crushing it to powder. It is then sifted to 
various degrees of fineness, and graded according to the meshes 
of the sieve. Emery is next in hardness to diamond dust and 
crystaline corundum, and it is used chiefly as an abrading agent. 
Prior to the invention of vulcanite, emery wheels were made by 
mixing clay and emery in suitable mounds, and vitrifying them 
like common earthenware. In rubber mills it is chiefly used in 
the manufacture of what are known as vulcanite emery wheels. 
It is also used in grinding and sharpening compounds, as hones 
and strops. (See also Alumina and Corundum.) A certain 
amount of it also gives the desired surface to rubber blackboards. 

Farina. — This is sometimes used in small quantities in un- 
usual mixtures as a compound, but has little value, as there are 
many better substitutes for it. A practical use for it, however, is 
the brushing of a rubber surface with it before vulcanization, 
when it is necessary to have printing or stamping done upon that 
surface afterwards. Farina is made largely of potatoes, another 
name for it being Potato Starch. The process consists simply of 
crushing, sifting, washing, bleaching, and grinding, which is re- 
peated three times, and each time the starch granules separate 
and are collected. Potato Starch will be remembered by rubber 
manufacturers as the material which the gossamer makers used 
successfully for a number of years in the production of the "elec- 
tric" or "corruscus'' finish. Bone ash is used sometimes in the 
place of Farina, where rubber surfaces are to be printed upon. 

Feldspar. — A name given to a group of silicates of which 



FELDSPAR— FOSSIL FARINA. 69 

the principal ones are Orthoclase or potash, containing silica, alu- 
mina, and potash, and having a specific gravity of 2.5 ; Albite, con- 
taining silica, alumina, and soda, specific gravity 2.61 ; Oligo- 
clase, containing silica, alumina, soda, and lime, specific gravity 
2.66; and Anorthite, containing silica, alumina, and lime, with a 
specific gravity of 2.75. The feldspars by the action of the weather 
break down into china clay, kaolin, or pottery clays. Ground very 
fine, they have been used in the production of rubber enamels and 
lacquers. 

Fire Clay. — A kind of clay which, better than any other, 
resists the action of heat and direct flame. It is composed prin- 
cipally of silica and alumina, with traces of the alkali earths. The 
best is found in conjunction with coal, and is called Stourbridge 
clay. Its specific gravity it about 2.5, and its color dirty white. 
Mixed with vulcanized India-rubber, dissolved in tar oil and sul- 
phur, it forms a compound which, when applied to hot joints, 
cures at once. 

Flint is practically pure silica and has the specific gravity 
of 2.63. The nature of the powder obtained by grinding is al- 
ways sharp and gritty. It is unacted upon by all ordinary means, 
and with difficulty even in the laboratory of the chemist. Its prin- 
cipal use, perhaps, is in the manufacture of glass. Flint varies in 
color from yellow and brown to black. It has been used in era- 
sive rubbers, although pumice stone is better. 

Flour of Glass. — Glass powdered and sifted through a fine 
sieve of 150 meshes to the inch. Glass varies much in its com- 
position, the more common kinds containing lime, while the so- 
called flint glass contains lead. Potash and soda also enter into 
the composition of glass; hence all flour of glass will contain 
those ingredients which entered into the composition of the glass 
it was obtained from. Generally speaking, Flour of Glass may 
be considered an inert substance under ordinary conditions, though 
the softer kinds are attacked even by boiling water. It was used 
by Newton and Wray in insulated wire compounds, and has also 
been used in certain packings. 

Flour of Phosphate. — See Phosphate of Lime. 

Fossil Farina, also called mountain milk, is an earth similar 
to infusorial earth. It is obtained from China and consists of sil- 



70 FILLERS IN DRY MIXING. 

ica 5c4, alumina 26|, magnesia 9, water and organic matter 13, 
with traces of lime and oxide of iron. It has been used in rubber 
compounding for the production of packings and semi-hard 
valves. 

Fossil Meal. — A kind of earthy mineral, principally com- 
posed of the minute shells of very small animals long extinct. It 
is similar to infusorial earth, lime and silica entering chiefly into 
its composition. It is used for the same purposes as infusorial 
earth (which see) or silica. 

French Chalk. — This is ground and sifted talc, forming a 
white, greasy-feeling powder. Its chemical composition is hydra- 
ted silicate of magnesia, the water being chemically combined. 
Its specific gravity is 2. (See Talc.) 

Fuller^s Earth. — A kind of clay. It is a greenish or brown- 
ish earthy, somewhat greasy-feeling, substance, having a shining 
streak when rubbed. Its composition is : Silica 70, oxide iron 2.5, 
alumina 3.5, lime 6, combined water 16, magnesia trace, phosphoric 
acid trace, salt 2, alkalies trace. Fuller's Earth is found in exten- 
sive deposits in England, where its annual consumption at one 
time exceeded 2,000 tons, chiefly in the woolen manufacture, for 
fulling cloth. Its specific gravity is from 1.8 to 2.2. It is used in 
rubber compounding for about the same purposes as infusorial 
earth, and is also used in the manufacture of rubber type. 

Graphite. — See Plumbago. 

Gypsum. — See Sulphate of Lime. 

Infusorial Earth. — This is obtained usually from deposits 
at the bottom of inland waters, and consists of the minute siliceous 
remains of infusoria or microscopical animals. It is known also 
as fossil flour, mountain flour, and infusorial flour. The largest 
deposits, in the form of a fine white or pinkish powder, are found 
in Nova Scotia and in Germany. This earth is a wonderful non- 
conductor of heat, and, in connection with asbestos, is used in the 
manufacture of boiler coverings. It is used also in small propor- 
tions in various rubber compounds, where it increases both 
strength and resiliency, though if used in excess it makes a very 
hard compound. The best grades are wholly free from vegetable 
matter, are nearly pure silica, and perfectly indifferent to corrosive 
substances. Under the name of diatomaceous silica it is used in 



IRON PYRITES— LIME. ■ 71 

a formula for elastic valve packing, patented by A. B. Jenkins, 
United States. This packing is described as practically indestruc- 
tible in steam or water, oils, acids, etc. 

Iron Pyrites. — A sulphuret of iron, commonly of a bright, 
brass yellow color; a very plentiful mineral often mistaken for 
gold. It is used in the manufacture of sulphuric acid, while sul- 
phur is also obtained from it by sublimation. It was used by 
Warne, Fanshaw, and others in the manufacture of packings to 
resist a high degree of heat. The sulphur in Iron Pyrites has also 
been used in vulcanization. Warne, in one of his heat resisting 
packings, patented the use of Iron Pyrites, and, in the compound 
that he gives as an example, leaves out the whole or a portion of 
the sulphur usually employed. (See Vulcanization.) 

Kermes. — A brownish red form of sulphide of antimony, 
artificially prepared by boiling in carbonate of soda. If left to 
itself the solution will partly deposit a very fine powder of Kermes, 
while the clear solution may be further treated with a weak acid 
to obtain the remainder. Kermes will not vulcanize rubber with- 
out the addition of sulphur. Its specific gravity is about 4.5. Its 
composition is 28 per cent, sulphur and 72 per cent, antimony. It 
is rarely used in rubber compounding. 

Lime. — The oxide of the metal calcium. It is commonly 
known in two states, viz. : Quick Lime, which is the pure oxide, 
and Slaked Lime, which is the hydrated oxide mixed with some 
carbonate. Quick lime is a white solid substance of specific gra- 
vity 3.2. It is not stable, taking up water and carbonic acid from 
the air and breaking down into a fine white powder, usually called 
air-slaked lime. Its power of absorbing water has caused it to be 
favorably used in drying operations, while the insoluble com- 
pounds it forms with various oils have led to its being considered 
as a drier, although this action is not properly to be called one of 
drying. Lime air slaked is used in rubber work, where there may 
be a little moisture in a compound, which it readily neutralizes. It 
is also used in soft cements in connection with tallow and India- 
rubber, but only where the rubber has been melted and the cement 
is of the non-drying variety. In compositions like that of Sorel's, 
Lime is introduced to effect a combination between resin acids 
found in the resin and resin oil. Excess of Lime in India-rubber 



72 FILLERS IN DRY AUXIN G. 

is injurious, because it renders the compound too open, thus induc- 
ing oxidation. When used in small quantities, aside from its effect 
upon moisture, it combines with free sulphur and modifies its 
continued action upon the rubber. It must be remembered, how- 
ever, that lime diminishes the resiliency of India-rubber, while it 
increases the hardness of both hard and soft rubber. It may be 
used in small quantities in insulated wire, and in a measure assists 
the insulating capacity of the rubber. Calcium carbonate, in con- 
nection with colcothar and methol alcohol, is used as a compound 
for cleansing vulcanite. Rubber also cures quicker when com- 
pounded with Lime. 

Litharge. — One of the oxides of the lead, known as the 
monoxide. When pure its specific gravity is 9.36. Commercial 
litharge often contains carbonic acid gas and water taken up from 
the air. These may be removed by strong heating. It has a pecu- 
liar property, the nature of which is yet a debated question, by 
virtue of which it renders oil more easily oxidized, or, as it is com- 
monly called, rendered dry. There is no reason to suppose that 
this action is available with caoutchouc. The best Litharge is 
made from pig lead, which is placed in a reverberatory furnace 
and exposed to a current of air, which reduces it to an oxide. It 
has been noted in rubber factories that certain men seem specially 
sensitive to the effects of Litharge, often developing serious symp- 
toms of lead poisoning. Persons who show any symptons should 
pay scrupulous attention to personal cleanliness. It is said that 
such persons have been cured by tajcing them out of the mixing 
room entirely, and putting them to work on vulcanizers, particu- 
larly where they open and handle the goods from the finished heat, 
the theory being that the sulphur fumes neutralize the effects of 
the leads. Possibly there is a grain of wisdom in this, for the 
old fashioned treatment for lead poisoning was sulphur baths and 
the drinking of water acidulated with sulphuric acid or the acid 
or sulphate of magnesia. Litharge is not only a valuable filler 
for rubber, but has the faculty of hastening vulcanization in a 
marked degree. All dry heat goods depend upon it, and in mold 
work and general mechanical goods it is used whenever possible. 
Of course, it is generally available for dark or black effects only. 
LiTHOPHONE. — See Colors. 



MAGNESIA— MICA. 73 

LiTHARGiTE. — A substitute for litharge, made of a mixture 
of pulverized and calcined magnesia and oxide of lead. 

Magnesia. — The oxide of the metal magnesium. A white 
dry powder which, when mixed with water, forms a hard com- 
pact mass like marble. Its specific gravity is 3.65. It is earthy 
in its nature, having no taste, but producing a sense of dryness in 
the mouth owing to its absorption of the water therein. It is fre- 
quently called calcined magnesia from the method of preparation 
by burning magnesia alba. Its use in rubber is to increase its 
toughness and resiliency, which it does to a marked degree when 
used in moderation. Magnesia is also used in the production of 
compounds like balenite, its use in hard rubber compounds being 
to increase resiliency as well as hardness. A very small quantity 
of it is also used in compounds for insulated wire, where it is 
said to increase the insulating qualities of rubber. Carbonate of 
magnesia occurs native in the mineral magnesite and, in connec- 
tion with carbonate of lime, as dolomite. 

Manganese. — A metal of the iron group; gray or reddish 
white in color, and must be kept under rock oil or in well sealed 
vessels, being easily destroyed by the air. Its specific gravity is 
7.2. Manganese is obtained artificially as a black powder, by ex- 
posing the peroxide to prolonged heat. When ignited it is con- 
verted into a red oxide, which corresponds to the black oxide of 
iron. The black Manganese of commerce is the peroxide. Oxides 
of Manganese have a destructive efifect on rubber and blacks that 
contain this, as they sometimes do, are to be avoided. Mangan- 
ese is used in connection with pitch, turpentine, and Gutta-percha 
for making Brandt's cement. 

Marble Flour. — This is the finely ground chips of white 
marble, and is composed almost wholly of carbonate of lime. It 
is a heavy inert powder, often used in rubber compounding as a 
susbtitute for barytes. It has also been used to some extent in 
hard rubber, and in the manufacture of hones. 

Massisot.— An oxide of lead, dull red orange in color. A 
higher degree of oxidation turns this into a product called 
Minium, which is its purest state. It is often used in rubber com- 
pounds, acting practically like litharge. 

Mica is the name given to a group of complex silicates con- 



74 FILLERS IN DRY MIXING. 

taining aluminum and potassium, generally with magnesium but 
rarely with lime. Their specific gravity ranges from 2.8 to 3.2, 
while their color varies greatly. Ground mica is simply one or 
other of these micas reduced to powder. It is used in rubber 
compounding chiefly for insulating purposes. It is handled as a 
cement, compounded with rubber, and cut with benzine, or may be 
mixed dry on the grinder. It is also used in fireproof coverings 
in connection with rubber, and it is said that for a semi-hard result 
that is to come in contact with hot water, rubber and Mica forms 
the best compound. Mica in a state of a very fine powder is also 
known as "cat's gold" or "cat's silver." 

Mineral Wool. — Produced by sending blasts of steam 
through molten slag, which reduces the fluid metal to a fiber 
similar to the fused glass that is spun into glass silk. Natural 
mineral wool, such as is found in the Hawaiian Islands, is very 
brittle, but the artificial has considerable toughness. It is also 
known as slag wool, or silicate cotton. It appears in light fleecy 
masses, and at a distance looks like fine cotton batting. It is very 
cheap, but is easily affected by weak acids, and should be kept 
away from a moist atmosphere. It has not been largely used in 
rubber work as yet, but Lascelles-Scott strongly advises its use, 
giving as reasons its cheapness and its physical fitness. The sul- 
phides present in it also assist in vulcanization. 

Minium. — One of the oxides of lead, known also as Red 
Lead (which see). It is a scarlet crystaline and granular powder, 
having a specific gravity of 8.6 to 9.1. On heating, it temporarily 
changes color to violet and black, but returns again to the scarlet 
on cooling. It is adulterated with oxide of iron and brick dust. 

Mountain Flour. — See Infusorial Earth. 

Orange Mineral. — A red lead made from carbonate of lead, 
while red lead is made from litharge. As a general rule, it con- 
tains some lead carbonate. It differs from red lead in color, in 
that it is more orange red, and more brilliant. The reason for 
this difference is that it is less crystaline, its particles being much 
finer than those of red lead. The pigment is also more bulky and 
much smoother. It is used in finer grades of dark rubber, to assist 
the cure and impart resiliency. 

, Oxide of Aluminum. — See Alumina. 



THE OXIDES. 



75 



Oxide of Antimony. — There are really three of these oxides. 
The tri-oxide, one most useful in the arts, is a snow white pow- 
der of the specific gravity of 5.2. It may be obtained by treating 
stibnite or, better still, powdered antimony metal with nitric acid, 
in a current of air sufficient to carry off the copious fumes arising 
during the operation, or by treating the chloride of antimony with 
cold water for several days. A mixture of the tri-oxide with a 
small percentage of the insoluble peroxide may be obtained by 
melting antimony in a cast iron retort fitted with nozzles, through 
which air may be blown so as to bubble through the melted metal. 
Dense white fumes arise, which may be condensed in suitable 
chambers into a snow white powder. This is used in coloring 
dental vulcanite. 

Oxide of Gold. — As a matter of curiosity it may be noted 
that this is the most costly ingredient suggested for rubber com- 
pounding. It occurs in two forms — ^the protoxide, a dark green 
or bluish violet powder, and the teroxide, a brown powder. The 
use of the protoxide was patented by Ninck. For dental vulcan- 
ite is is doubtful if either form of the oxide could be used, even 
if the price were so low as to bring it within reach. Another 
formula calls for the mechanical admixture of gold leaf, which 
is practicable — if one possesses the gold. 

Oxide of Lead. — See Minium and Litharge. 

Oxide of Tin. — The article most frequently used in the arts 
is the di-oxide. This is a white water-free powder, of the specific 
gravity of 6.7, insoluble in acids and such solvents as naphtha, 
petroleum, etc. It is infusible, except at a very high temperature, 
and is tasteless and inodorous. What is known as French Oxide 
of Tin is simply a carefully prepared and purified form of the di- 
oxide. It is rarely used in rubber work, although Newton recom- 
mends it for a basic ingredient in rubber type. The other oxides 
of tin are at present merely of chemical interest. 

Oxide of Zinc. — See Colors. 

Oxychloride of Lead. — There are several oxychlorides of 
lead. The substance once known as Turner's Yellow and another 
known as Carsel Yellow were both of this composition. More re- 
cently a white compound has been prepared, which, from its cover- 
ing power, has been used largely as a paint. Tarpaulin compounds 



76 FILLERS IN DRY MIXING. 

consisting of India-rubber, coal tar, and pitch are treated with 
Oxychloride of Lead for surface drying, in lieu of vulcanization. 

Pagodite. — A mineral resembling steatite or soapstone. Its 
name comes from its having been used in the East as a material 
for carving miniature temples or pagodas from, as it is soft enough 
to be cut with a knife. Its specific gravity is about the same as 
that of soapstone, and its color greenish white. (See Agalmato- 
lite.) 

Paris White. — This has exactly the same composition as 
Whiting, but is a much harder and more compact form of English 
chalk, and therefore has greater density. Spanish White is a 
coarser variety of the same material. Its uses are practically the 
same as those of whiting. 

Petrifite. — A white powder composed of two inexpensive but 
secret substances. When mixed with water it solidifies quickly, 
and is an excellent binding substance. Mixed with marble dust, 
it is sometimes melted and cast upon glass or other smooth sur- 
faces, and makes an excellent table top in place of the zinc tables 
used in many rubber factories. As it is perfectly impervious to 
ordinary solvents, neither cement nor India-rubber sticks to it. It 
is manufactured in England. 

Peroxide of Lead. — The highest oxide of lead — a dark 
brown powder with a specific gravity of about 9. It is easily 
decomposed, and from this characteristic it has a strong oxidizing 
adtion. Exposed to sun light or to heat, it yields oxygen and 
passes into the lower oxide known as Red Lead. Its oxidizing 
properties make it a questionable ingredient in compounding rub- 
ber, although certain formulas call for its presence. 

Peroxide of Manganese. — Another name for Black Oxide 
of Manganese, which is a black powder having a specific gravity 
of 4.8. It is not readily acted on in ordinary ways, being un- 
changed by heat short of bright red. It is insoluble in the ordi- 
nary hydrocarbon solvents. Solvent naphtha was treated with 
Peroxide of Manganese by Humphry to free it from water. ( See 
Manganese. ) 

Phosphate of Lime. — The chief constituent* of animal bones, 
forming the bulk of the ashes of the same when burnt. It is a 
white powder, and when in crystaline mineral form, it has a 



PHOSPHORUS. yy 

specific gravity of 3.18. It is insoluble in ether, alcohol, or the 
benzine class of solvents. As it occurs naturally it is known as 
flour of phosphate and is used in part as a substitute for whiting. 
Bone ash made from animal charcoal is used in the same way. 

Phosphorus. — A non-metallic element or metalloid, although 
in its combining relation it is more closely connected with arsenic 
and antimony than with any members of the sulphur group. It 
is found ordinarily in two states — the ordinary phosphorus and 
the red variety. Ordinary phosphorus is an almost colorless or 
faintly yellow solid substance, somewhat resembling wax, and 
giving off a disagreeable odor. It fuses at 111.5° F- ii^to a color- 
less fluid. Heated in the air to about 140° F., it catches fire and 
burns with a bright white flame. It dissolves freely in benzol, 
bisulphide of carbon, and in many oils. Red phosphorus is an 
amorphous powder of a deep red color, with no odor, and may 
be heated to nearly 500° F. without fusing. Its specific gravity is 
2.10. It does not take fire when rubbed, undergoes no change on 
exposure to the air at ordinary temperatures, and is far less inflam- 
mable than ordinary Phosphorus. It is insoluble in solvents of the 
ordinary Phosphorus, and is not poisonous. Mulholland made 
an insulated wire compound from shellac and India-rubber in 
solution, combined with i to 2 per cent, of Phosphorus, which he 
cured with chloride of sulphur. As cold-cure gums are of little 
value as insulators, his invention is of doubtful value. He also 
made a prepartion of India-rubber, resin and tallow, and shoddy, 
to be applied in a fluid state where gas came in contact with the 
rubber, adding Phosphorus after his solution was finished, to pre- 
vent decomposition of the rubber. Duvivier also treated Gutta- 
percha with sulphide of phosphorus, claiming that he got an elas- 
tic result, but allowing that his compound was damaged by acid 
vapors, to neutralize which action he mixed carbonate of soda with 
it. An anti-fouling preparation of English origin was also made 
of Gutta-percha, turpentine, and a little Phosphorus. 

Pipe Clay. — A peculiar kind of clay containing neither iron, 
sand, nor carbonate of lime. It is a beautiful white, retaining its 
whiteness when burnt. It belongs to the group of clays. Its spe- 
cific gravity is 2 to 2.5. It was used by Mayall in combination 
with Gutta-percha, India-rubber, zinc, shellac, and resin for insu- 



78 FILLERS IN DRY MIXING. 

lating tape, and by Day to absorb gases during vulcanization. 

Plaster of Paris. — This is prepared from gypsum or sul- 
phate of lime. Its properties of hardening when made into a paste 
with water are well known. Its chemical properties are the same 
as burnt gypsum. It is used sometimes instead of lime in com- 
pounding and also for making trial molds for rubber work. It was 
used in old fashioned dry heat compounds to prevent blistering. 
(See Anhydrite.) 

Plumbagine. — A dark colored pigment manufactured in 
England and sold to rubber manufacturers for the production of 
valves. By its use the rubber is vulcanized and goods made which 
are said to resist successfully the action of cheap lubricants. One 
pound of Plumbagine is used to 2 pounds of rubber. 

Plumbago. — This sometimes is called Black Lead, though 
having no relation to lead; it is also called Graphite. Its specific 
gravity is 2.1 to 2.2. Its color is black and shiny. It consists 
chiefly of carbon, but contains more or less alumina, silica, lime, 
iron, etc. varying from i to 47 per cent., but not chemically com- 
bined. Black Lead is a perfect conductor of electricity. It is 
more incombustible than most ingredients used in rubber com- 
pounding, and is capable of withstanding great heat. It is used 
in the rubber industry, chiefly in the manufacture of what are 
known as graphite or plumbago packings. It is a wholly inert 
substance, safe to use in connection with any compounds, and is 
not affected by heat or acids, alkalies, or corrosive substances. It 
is useful also in certain polishing compositions made with India- 
rubber as a base. German asbestos cements almost all contain a 
good proportion of finely powdered graphite. 

Portland Cement is obtained by burning the mud found at 
the mouths of several large rivers in Europe with a proportion of 
clay and lime. Its composition is somewhat complex, containing : 
Lime 55 to 63 per cent., silica acid 23 to 26 per cent., alumina 5 to 
9 per cent., and oxide of iroH 2 to 6 per cent., together with mag- 
nesia, potash, soda, sulphate of lime, clay, or sand in various small 
proportions, according to the mode of manufacture. Its value 
as a cement depends upon the interaction of the lime and the silicic 
acid. In compounding it would have no chemical effects upon 
rubber, but might of itself become much hardened and thus cause 



CEMENT— PUMICE STONE. 79 

mechanical injury to goods in which it has been introduced. As 
it occurs commercially, it is a gritty powder of a gray brown or 
yellow brown color. The gray brown makes the best cement. Its 
only use as far as known in rubber is where it is mixed with tar 
oil and waste rubber to joint pipes containing fluids. 

Powdered Coal. — Coal consists chiefly of carbon, and is 
universally regarded as being of vegetable origin. Various coals 
differ widely in their composition and characters, running from 
the softest kinds of earths to compact and solid bodies like Parrot 
coal, which is so compact and solid that it has been made into 
boxes, inkstands, and other articles which resemble jet. The aver- 
age specimen of coal analyses is : Carbon 82.6, hydrogen 5.6, oxy- 
gen 1 1.8. Some curious compounds of India-rubber and Coal have 
been formed. One, for instance, was a mixture in which 2 pounds 
of waste India-rubber in a cheap solvent was mixed with nearly 
a ton of powdered Coal, in which was a certain amount of clay and 
peat, the use being for an artificial fuel; another use was in the 
production of hard rubber. Indeed, it is probable that the cheap- 
est compound in use to-day is a jet black, semi-hard rubber made 
almost wholly of powdered bituminous Coal in which is incorpo- 
rated a very small percentage of rubber. Coal that is to be used 
in any rubber work should be submitted to a chemist and its sul- 
phur and other compounds carefully determined before use. 

Pumice Stone. — ^A light porous ashy stone, the product of 
volcanic action, its structure being that of a mass of porous glass. 
Its composition is a mixture of silicates of aluminum, magnesia, 
calcium, iron, potassium, and sodium, varying with the particular 
lava whence it had its origin. Its action on India-rubber will be 
quite inappreciable, chemically speaking, but its mechanical action 
will be that of a sharp cutting powder. Ground fine, it is used 
in the manufacture of erasive rubber, and is also used compounded 
with the rubber in the manufacture of hones. Recent patents call 
for its use in certain semi-hard compounds, its presence being said 
greatly to increase the toughness of the compound. Mixed with 
lard oil to a thick paste, this has been used for polishing India- 
rubber. 

PuzzoLANA. — A porous lava found near Naples, used chiefly, 
when mixed with ordinary lime, forming hydraulic cement. Com- 



8o FILLERS IN DRY MIXING. 

pounded with marine glue, it is used as a varnish for preserving 
metallic ahicles from corrosion. 

Red Chalk. — Artificially deposited chalk colored by any 
suitable pigment— usually one of the red oxides of iron. (See 
Chalk.) 

Red Lead. — An oxide of the metal, which is also known as 
Minium. Prepared from pure massicot or from white lead. Its 
specific gravity is 8.6 to 9.1. A scarlet crystaline granular pow- 
der, of rather strong coloring powers. As a colorant in rubber 
work it would be unavailable, since the sulphur necessary to vul- 
canize would render it more or less black, owing to the formation 
of sulphide of lead. It is sometimes used, however, in place of 
litharge. It is also used in "hot" cements of Gutta-percha and 
for varnishes such as those made of India-rubber, linseed oil, etc., 
for covering the backs of mirrors. (See Minium, Massicot, and 
Orange Mineral.) 

Rotten Stone. — Usually considered to be the residuum of 
naturally decomposed impure limestone, and varying in composi- 
tion with its sources. That from Derbyshire, England, shows 
much alumina; other sorts have more silica. The name is some- 
times given to "tripoli" which is a species of infusorial earth. It 
can have no particular action on rubber, as it is very inert, but is 
used in certain packings, and was also used by Warne in insulated 
wire compounds. 

Selenium. — A non-metallic element or metalloid of a dark 
brown color, analagous to sulphur. It has no smell, is tasteless, 
and is a non-conductor of electricty. It occurs rarely in nature, 
being found chiefly as a selenide in combination with lead, silver, 
copper, or iron. It is the basis of a process for vulcanizing India- 
rubber. 

SiLEX. — Pure silica. (See Flint.) 

Silica. — The oxide of the metal silicon, familiar in the forms 
of flint, quartz, etc. Its specific gravity is 2.6. It is without action 
on India-rubber, except mechanically speaking. It is used in 
Chapman's vulcanite enameling solution, made of Inida-rubber, 
sulphur, and Silica. (See Flint.) 

Silicate Cotton. — See Mineral Wool. 

Slag Wool. — See Mineral Wool. 



SLAKED LIME—SOAPSTONE. 8i 

Slaked Lime. — Quick lime that has been treated with water, 
and allowed to absorb it from the air and crumbled to a fine pow- 
der. (See Lime.) 

Slate. — A soft easily laminated earthy material, chiefly alu- 
minuous in composition, and allied to the clays. Finely ground, 
it makes a good semi-hard valve of a blue gray shade. It has 
been also used in general rubber compounding. 

SoAPSTONE. — A silicate of magnesia, combined with more or 
less alumina and water. It is really a massive form of talc. In 
color it is white, reddish, white, or yellow, is soft and greasy to 
the touch, is easily cut, but is hard to break. Its specific gravity 
is 2.26. It is used often in the place of French talc, for keeping 
rubber surfaces from sticking together during vulcanization, and 
also for burying dark colored goods and holding them in shape 
while they are being cured. Used as an adulterant for rubber, it 
makes an excellent semi-hard compound for valves. It is also 
used as a basis compound in the manufacture of insulated wire. 
(See Talc.) 

Starch. — A vegetable substance allied closely to cellulose. 
It occurs in irregular lumps, composed of granules which have a 
definite character, according to the variety of plant they were taken 
from. When dry its specific gravity is 1.53. Commercial Starch 
contains usually about 18 per cent, of water and, if kept in a damp 
place, will absorb 33 per cent, of water. It was much used for- 
merly on solarized work. Torrefied Starch is obtained by roasting 
the common form, and is used in artificial leather compounds. 

Stibnite. — That ore of antimony known usually as black 
antimony. (See Kermes.) 

Sublimed Lead. — Used in the rubber manufacture, it acts 
both as a filler and chemically. Its peculiar velvety fineness makes 
it mix intimately with the rubber, and gives a very fine finish, 
showing no shiny crystals on the surface. The oxide of lead' in 
the Sublimed Lead will also bind free sulphur in the rubber. The 
amorphous state of the Sublimed Lead makes the action of the 
lead oxide in this much more effective than the action of litharge, 
and the result is a very smooth lively jet black rubber. 

Sugar of Lead. — See Acetate of Lead. 

Sulphate of Lead. — A white powder of the specific gravity 



82 FILLERS IN DRY MIXING. 

of 6.2, insoluble in water, but readily soluble in caustic alkalies. 
It is not a very stable compound. In Coole/s formula for arti- 
ficial leather, which has Gutta-percha for a base, it is used in con- 
nection with dextrine, magnesia, and cotton dust. 

Sulphate of Lime. — Also called Gypsum. A common min- 
eral occurring under various forms and names as alabaster, selen- 
ite, and gypsum earth. It is pure white in color and has a specific 
gravity of 2.33. Plaster of paris is a burnt form of gypsum. In 
the ordinary recovery of rubber by the acid process, whiting be- 
comes gypsum. (See Anhydrite.) 

Sulphate of Zinc. — Also called White Vitriol. It occurs 
in the form of a transparent crystal containing about 44 per cent, 
of water of crystalization, 87 per cent, of which is not given up 
short of a red heat. Its specific gravity is about 2.03. 

Talc or French Talc is a mineral allied to mica. It is com- 
posed entirely of silica and magnesia, in the proportions of 6y to 
73 of silica, 30 to 35 of magnesia, and 2 to 6 of water. Its colors 
are silvery white, greenish white, and green. Talc slate is more 
like steatite and is used for similar purposes. French Talc is used 
very largely in rubber factories in all lines of work for preventing 
surfaces from sticking together, during either manipulation or 
vulcanization. It is used also sometimes for dusting molds to pre- 
vent the gum from sticking to the metal and is used largely to 
bury white goods and keep them in shape during vulcanization. It 
is used sometimes in compounding, but any great amount of it 
produces a stony effect. It makes, however, an excellent semi- 
hard packing. It is used further in compounds for soft polish- 
ing, with India-rubber as a binding material. ' 

Talite. — A white earthy material used in general rubber 
compounding. It is allied to diatomaceous earth, presumably, and 
has the same usage. Its analysis shows: Moisture 5.59, silica 
83.9, sesqui-oxide of iron 1.2, alumina 2.8, oxide of manganese 
trace, potash trace, combined water and organic matter (by igni- 
tion) 6.47, loss and undetermined 0.04 — ^total 100. 

Tripoli. — See Rotten Stone and Infusorial Earth. 

Wheat Flour is used in making matrices for rubber stamp 
work, and sometimes as a compounding material in India-rubber, 
though this is not to be advised, as the flour is apt to turn sour. 



WHITING— WHITE LEAD. 83 

A large and important use for it has been in the dusting of black 
goods, such as rubber coats, so as to keep them from sticking 
together, should they accidentally touch during dry heat of vul- 
canization. Wheat Flour is preferable to almost anything else, 
for the reason that it washes off after vulcanization, without leav- 
ing any trace in color or stain. It is, of course, used on the goods 
known as "dull finished." 

Whiting, or Chalk, as it is often called, is carbonate of 
lime. It is a white earthy material of the specific gravity of 
2.y to 2.9. It is made from English chalk, which is crushed, float- 
ed, and run through a filtering process, and dried in cakes, out of 
which, by a system of dry grinding and bolting, it is made in 
varying degrees of fineness. Where Whiting is kiln dried hastily, 
or under extreme heat, it is apt to become calcined, which gives it 
a hard, gritty feeling. Air dried whiting is considered the best. 
Whiting is in reality a purified form of carbonate of calcium, of a 
very soft or flocculent quality. The finest grades are known as 
"gilders^ " and "extra gilders'.'^ It is used more generally in rub- 
ber compounding than any other material, except sulphur. Used 
moderately, it increases the resiliency of rubber, but adds to the 
hardness. It does not, however, produce the stony effect that 
many ingredients give. It is also the basis of the molds used in 
rubber stamp making; paste being made of whiting, wheat flour, 
gule, and carbolic acid. Whiting is liable to absorb considerable 
quantities of water from the air. It is customary in many mills, 
therefore, to keep it in large bins that not only are covered but 
have steam pipes in the lower portions to drive out any moisture 
from the material. 

White Lead. — This is a carbonate and is a heavy white pow- 
der. It is unstable in color, however, as sulphur compounds, espe- 
cially in the gaseous forms, easily attack it and blacken it by rea- 
son of the formation of sulphide of lead. Its specific gravity is 
6.46. Sometimes it is adulterated with lead sulphate, chalk, car- 
bonate, or sulphate of baryta, or pipe clay. The simplest test for 
the purity of White Lead is to heat it in a thin glass vessel with 
some very dilute pure nitric acid; if pure it will dissolve com- 
pletely. If chalk is present it also will pass into the solution, in 
which it may be detected by the addition of caustic potash, throw- 



84 FILLERS IN DRY MIXING. 

ing it down as a white cloud. The best carbonate of lead is made 
by an old fashioned process, by placing metallic lead surrounded 
with spent tan bark in stacks, where it comes in contact with weak 
acetic acid. The heat of the bark volatilizes the acid and oxidizes 
the lead, while the acetic acid changes the oxide into acetate of 
lead, and this in turn is converted into carbonate by the carbonic 
acid given off by the heated body. This process of corrosion 
requires from six to eight weeks. There are many later and more 
rapid processes ; for instance, take either litharge or acetate of 
lead, and expose them to a current of carbonic acid gas. etc. 
The original "triple compound" patented by Goodyear consisted 
of India-rubber, sulphur, and White Lead. A white lead known 
as sublimed lead is used very largely in the rubber manufacture. 
It is a fine white amorphous powder and imparts a decided tough- 
ness to rubber compounds. (See Sublimed Lead.) 

UNUSUAL INGREDIENTS IN DRY MIXING. 

It is not strictly accurate, perhaps, to say that it is unusual for 
fibers to be incorporated in rubber mixtures, for stocks made 
from unvulcanized rubber clippings have been used for years. 
Inner soles for rubber footwear and mats and molded articles 
have long been made of stocks of this kind, the fibers being cot- 
ton and wool, chiefly. Where wool was present there was often- 
times danger of blistering from the oil in the fiber, but this was 
easily gotten over by special compounding. In addition to the 
fibers already noted, silk, flax, jute and hemp — in fact, almost 
all of those in ordinary use — have been utilized, being added to 
the compounds to give toughness to them. The goods in which 
they are usually put are packings, artificial leathers, tire treads, 
and for wearing surfaces. 

A fiber that has attracted considerable attention for this 
work, and one for which a number of patents have been granted, 
is cocoanut fiber, which is recommended for packings. Certain 
kinds of moss have also been used, as have sponge cuttings, peat, 
and wood pulp. This last named material has been used both in 
packings and in insulated wire compounds. It is also the basis 
of a curious artificial rubber that appeared several years ago, un- 
der the name of Maltha, but is not to be confused with the pro- 



UNUSUAL INGREDIENTS. 85 

duct that has become almost universally known by that name. 

Sawdust of all kinds has also been incorporated in rubber, 
and was formerly used in making sponge rubber, until better com- 
pounds were discovered. Those who use vegetable fibers prefer 
them unbleached rather than bleached, and very often treat them 
to remove resins that may be present. A few of the many other 
vegetable substances that have been used are sugar and sugar 
charcoal and seaweed. (See Algin.) 

Animal substances are also valuable, as for instance, animal 
charcoal (which see), whalebone, which is called for in some of 
the Woodite patents, fur, tan-hair, leather fiber. Currier's skiv- 
ings, which are used in artificial leather, the white of eggs, etc. 

Under the head of earthy and metallic ingredients, almost 
anything can be used, although some metals have a bad effect on 
rubber, copper being the most notable of these. The unusual 
earthy matters are powdered fossil iron-stone, Wisconsin mine- 
ral, coke ashes, Stourbridge clay, powdered granite, salt, pow- 
dered lithographic stones, powdered oyster shells, powdered 
schist; and in metals, steel, and all other common metal borings, 
filings, and turnings. These latter have been incorporated in 
packings as a rule. One packing in particular, which has had a 
world-wide reputation, was heavily compounded with brass fil- 
ings. 

The deodorization of rubber, and the neutralization either of 
the smell of the rubber or its solvent, has brought out also a curi- 
ous line of ingredients. Musk, for example, has been used to dis- 
guise the earthy odor of Gutta-percha. Alcoholic infusions of 
sage-tea, lavender, and verbena have been used in fine goods, 
while in powdered form, ginger root, birch, orris root, sassafras, 
marshmallow root, sandal wood, and other sweet smelling ingre- 
dients have been incorporated. The leaf of the mint has also been 
mingled with copperas, and placed in dry heaters, while a more 
expensive process was that pursued by Hill, who passed a cur- 
rent of hot air over perfumes and into the heaters. It must not 
be imagined that the ideas expressed in the foregoing are un- 
worthy of the consideration of those who make ordinary cheap 
mechanical goods, for certain of these ingredients are used to-day 
in mechanical mixtures to overcome the odors of African rub- 



86 FILLERS IN DRY MIXING. 

bers. Essential oils and gums are also used for the same pur- 
poses, the descriptions of which will be found under their proper 
departments. 

Medical science has also added its list of ingredients to rub- 
ber compounding, chiefly in the line of adhesive plasters, where 
ingredients like dry mustard, menthol, capsicum, belladonna, and 
a great variety of other medicaments are incorporated with the 
rubber. 



CHAPTER VI. 

I. SUBSTITUTES FOR INDIA-RUBBER AND GUTTA-PERCHA. 

Rubber Substitutes^ as a rule, are made from oxidized oils. 
Those used most generally are made from linseed, rapeseed, cot- 
tonseed, mustard, peanut, or corn oils, acted on either by chloride 
of sulphur or by sulphur boiled with the oil at a high temperature. 
Substitutes have been known nearly fifty years, and have been 
made the subjects of many patents, but only within the last ten 
or fifteen years have they come into general use. French manu- 
facturers have long exported these goods; they were really the 
first to produce them commercially. The fact that Europeans 
were unable at first to get the results with reclaimed rubber that 
were secured in the United States, led them to go further in their 
experiments with oxidized oils and to exploit their uses more 
thoroughly. The substitutes on the market to-day are, as a rule, 
white, brown, and black. They are slightly heavier than pure 
India-rubber, but their specific gravity is so near that of rubber 
that their presence cannot be detected in rubber compounds by 
specific gravity tests. Substitutes of this type are easily analyzed 
by the expert chemists, and the results of such analyses are of 
value to rubber manufacturers. The table on the next page, con- 
taining analyses of typical sorts of substitutes, is adapted from Dr. 
Rob. Henriques*. 

It would be a mistake to suppose that rubber substitutes are 
of no value, for, as a matter of fact, they possess certain very dis- 
tinct advantages not found in simple mineral adulterants nor pos- 
sessed by any of the bituminous products now in use. Their 
value, of course, is where they cheapen stock without seriously in- 
juring its durability or changing its texture. Among the wiser 
of the manufacturers, where substitutes are compounded with 
rubber they are used in small quantities, sometimes only 5 per 
cent, being added, and rarely is more than 25 per cent, to be found 
in a good compound. 

Many substitutes, made from sulphurized drying oils, shorten 
the life of goods materially, by oxidizing the rubber. Manu- 

* Journal of the Society of Chemical Industry, 1894, page 47. 

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ADAMANTA—ELATERITE. 89 

facturers have learned, however, to avoid those that have this 
fault, and are becoming more and more expert in the use of these 
goods, as they have become in the use of the cheaper grades of 
African rubber and reclaimed rubber. 

The list following has been made quite comprehensive, not 
because all the substitutes described are deemed valuable, but 
rather to give a broad view of the subject. It will be noticed that 
many of these gums are far out of the line of sulphurized oil ex- 
periments. Resins, glues, asphalt, cellulose, seaweed, bastard rub- 
bers, animal substances, etc., have all been called upon, and some 
of the treatments have been as original as the ingredients are 
unusual. To the end that the perfect substitute may be found, 
and with the fullest appreciation that anything which suggests new 
experiments has its value to the manufacturer, many that other- 
wise would be ignored are given here. 

Adamanta. — The American name for a German substitute 
for India-rubber, made from linseed oil, sulphur, lime, and resin. 
It is a thick, black, gummy mass, with an odor similar to that 
of most of the sulphur oil substitutes, and showing a bright 
cleavage. It was at one time used largely in France and Germany, 
and introduced to some extent into the United States. Its chief 
use was in cheap mechanical rubber goods, and for insulation. 

Algin Gum. — A gluey, leathery substance, manufactured 
from seaweed. It is insoluble in cold water, alcohol, ether, and 
glycerine, and combines readily with alkaline and metallic bases 
to form substances, many of which are soluble. Algin can be used 
for waterproofing compounds, as it combines easily with rubber, 
shellac, and other gums. With many metallic bases it forms in- 
soluble compounds as tough as horn or as pliable as Gutta- percha. 
It is an English product. 

A. R. D. Gum. — So called because it is used as an anti-dry-rot 
compound. It is manufactured of 112 parts glue, 56 parts resin, 10 
parts boiled linseed, and 35 parts water. In some cases it has 
also been mixed with India-rubber in general compounding. Pat- 
ented by J. F. Ebner, London, England. 

Artificial Elaterite. — Made from liquid bitumen by incor- 
porating with it vegetable oils, such as cottonseed oil, palm oil, 
rapeseed oil, etc. The product is treated with aid of heat and pres- 



90 SUBSTITUTES FOR RUBBER. 

sure, with chloride of sulphur, saltpeter, and sulphur, which pro- 
duces an oxidization of the fatty substances. The result is an elas- 
tic rubber-like or leathery mass, which is soft, spongy, and gluey. 
This gum is said to be far more elastic than the best samples of 
mineral rubber, and is useful for waterproofing and insulation. 
Patented by W. Brierly, in England. 

Artificial Gutta-percha. — A French compound made of 
50 parts copal, 15 parts sulphur, 30 parts turpentine, and 60 parts 
petroleum. While mixing the heat reaches 100° C. ; it is then 
cooled to 35° C. Then there is added a solution of 3 parts case- 
ine, in weak amonia, and a little methylene, and reheated to 120° 
C. It is then boiled with a 15 or 20 per cent, solution of tannin, 
and 15 parts ammonia. After several hours' boiling it is washed 
and cooled. 

Black German Substitute. — Made of boiled linseed oil and 
sulphur, together with resinate of lime. This gum is similar to 
Adamanta, and has been practically driven out of the market by 
lighter substitutes. 

Blandite. — An artificial India-rubber invented by Dr. A. L. 
Blandy, of London. It is fairly elastic, stretching to about twice 
its length, and returning readily. It is very pliable and does not 
show signs of cracking when bent. It is vulcanized like ordinary 
rubber, and can be molded into any form desired. Coated on 
cloth, it strongly resembles leather. It is waterproof, and is used 
for gas tubing, mats, etc. In its crude form, it is a liquid mass 
resembling molasses. Dr. Blandy's patent describes the com- 
pound as made preferably of linseed oil which has been reduced 
by oxidation ; then 10 per cent, of bisulphide of carbon, to which 
has been added 10 per cent, of chloride of sulphur, is mingled 
with the oil, and brought by gentle heating to the desired con- 
sistency. Trinidad asphalt, cleansed and reduced to powder, is 
combined under the heat in the proportion of 3 parts to i of oil. 
Care must be taken to avoid fire in heating. These proportions 
are gradually brought, by heat and stirring, to a liquid or thin 
state, and when in this condition it must be poured upon a wet, 
cold surface, and thus cast into sheets, convenient for subsequent 
mixings. 

Carrol Gum. — A well-known sulphur oil substitute used in 



CHRISTIA GUM—ELASTEINE. 91 

the United States. In smell it has all of the characteristics of the 
sulphurized oil products. It is produced usually in granular form, 
and is very black. 

Christia Gum. — An English substitute for Gutta-percha or 
India-rubber, used as a surgical dressing. It is said to be com- 
posed of hemp fibers, so treated as to be impervious to both alcohol 
and water. Dieterich analyzed a sample of the product, and said 
that the fibers were sulphite wood pulp, and that the coating was 
made from chrome gelatine treated with glycerine, or the well 
known compound of glue, glycerine, and bichromate of potassium. 

CoRKALiNE is made of glue, glycerine, ground cork, and 
chromic and tannic acids. It is of English derivation and is used 
as a substitute in mat work. 

Corn Oil Substitute. — A sulphurized oil substitute similar 
to that made from oxidized linseed or rapeseed oils, manufactured 
from corn or maize oil. It is the cheapest oil substitute that has 
yet been put on the market. It is made in two colors, brown and 
straw color, and is used in large quantities in mechanical goods,, 
and in proofing. A good example of this type of substitute is 
that known on the market as "Kommoid." 

Dankwerth^s Russian Substitute. — This is said to be a 
perfect substitute for both Gutta-percha and India-rubber, and is 
used for covering telegraph cables. High temperatures do not 
affect it. It is made of i part by weight of the mixture of equal 
parts of wood tar, oil, and coal tar oil, with 2 parts of hemp oil 
heated until the mass is of the right consistency. Then 1-3 part 
by weight of boiled linseed oil is added. To this is added a little 
ozocerite and some spermaceti. It is then heated again, and finally 
a little sulphur is added. 

Elasteine. — An elastic substance produced through the 
treatment of certain resins. Solid and semi-solid copal resins are 
treated with oleic acid (found in stearine works), which entirely 
dissolves them. The product of the solution is soluble in spirits 
of turpentine and in oil. This solution of gums in oleic acid gives 
an opportunity to produce materials that have sometimes the elas- 
ticity and the consistency of India-rubber. The inventor advises 
their use in insulating wire and in various kinds of proofing. It 
i.s of French origin, and patented by M. Louis Riviere. 



92 SUBSTITUTES FOR RUBBER. 

Elastic Glue. — A mixture of dry glue and glycerine in equal 
parts, by weight. As little water should be used as possible in its 
manufacture. It is used for elastic figures, galvano-plastic molds, 
etc. It is not waterproof, nor will it stand a high degree of heat. 

Euphorbia Rubber. — J. G. Boles reduced euphorbia gum to 
a fine powder and, after drying carefully at a low temperature, put 
it in solution and finally hardened it by mixing it with earthy mat- 
ters and shellac. The same gum before that he mixed with a 
preparation of rubber and cured it, forming a kind of vulcanite. 

French Gutta-percha. — This gum is made by boiling the 
outer bark of the birch tree in water. The result is a fluid, which 
is very black, and which becomes compact and solid on cooling. 
It has been claimed that it possesses all of the good properties of 
Gutta-percha, and that in addition it does not oxidize when ex- 
posed to the air. Its application for industrial purposes has been 
patented. 

Fenton^s Artificial India-rubber. — Manufactured from 
linseed or similar oils, mixed with tar, pitch, or other forms of 
pyroligneous acid, the mixture being placed in a bath of diluted 
nitric acid, and allowed to remain for maceration until, by the 
action of the bath upon the compound, the whole is coagulated 
into a tough, elastic magna. The black "Fenton" contains as a 
coloring matter a small quantity of plumbago or black carbonate 
of iron. The gum is patented by Ferrar Fenton, London, Eng- 
land. In his specification he modifies it by taking the artificial 
gum described, and placing it in a bath composed of a solution of 
sugar of lead, oxide of zinc, saltpeter, or some other form of 
nitrate, and, if high flexibility is desired, adds 5 to 10 per cent, to 
copal gum and nitric acid diluted with water. These solutions are 
used one at a time, the proportion being 5 per cent, of sugar of 
lead, or, for greater hardness, 5 to y\ per cent, of saltpeter to the 
weight of the magma. Before vulcanizing, the substances are 
washed in an alkaline solution to remove acid. Fenton rubber is 
said to have been subjected to 320° F. for fifteen minutes, the 
only result being to increase its elasticity. 

Grape Rubber. — A high grade of artificial rubber, produced 
from the skins and seeds of grapes from which wine has been 
extracted by pressure. Small samples manufactured in the labora- 



FIBRINE—KERITE. 



93 



tory are said to be almost identical with pure rubber. It has been 
impossible so far to make the material on a large scale economi- 
cally and, therefore, none of the gum is on the market. 

Gum Fibrine is made of paper rags, treated with liquid car- 
bonic acid, mixed with resin and gum benzoin and castor oil, dis- 
solved in methylated alcohol. It is an English compound. 

GuTT ALINE. — A substitute for India-rubber and Gutta-percha, 
manufactured as follows : To Manila gum tempered with benzine 
is added 5 per cent, of Auvergne bitumen, also mixed with ben- 
zine. Then add 5 per cent, of resin oil, and allow 48 to 86 hours 
to pass between treatments. The product obtained is similar to 
India-rubber. If it is too fluid, the addition of 4 per cent, of sul- 
phur dissolved in bisulphide of carbon will act as a remedy. 

Insulite. — A preparation made of wood or vegetable fiber, 
finely ground and dessicated, and saturated with a mixture con- 
sisting of melted asphalt, incorporated with substances of the resin 
type, with or without substances of the paraffine or anthracine 
types. The products resulting are used as substitutes for India- 
rubber, particularly in insulation. Patented by Alfred H. Huth, 
London. 

Kelgum. — A linseed oil preparation manufactured in the 
following way: First, boiling linseed oil in a nitric acid bath 
until it reaches a gum-like condition; second, subjecting the gum 
to a bath for the removal of the acid; third, cutting the gum in 
a solvent bath; fourth, disintegrating the gum with the solvent; 
fifth, grinding the disintegrated mass ; sixth, boiling the material ; 
seventh, subjecting the same to another boiling, and adding a 
drier. Used in proofing compounds. Invented by Henry Kellog, 
United States. 

Kerite. — A compound of vegetable oils, coal tar, bitumen, 
and sulphur, to which is added sometimes a little camphor and 
various waxes. Occasionally sulphide of antimony is used in place 
of sulphur. Vegetable astringents, such as tannin, the extract of 
oak bark, etc., are also used in small quantities to impart tough- 
ness. Kerite is the invention of Austin G. Day, and has been used 
largely for the manufacture of a covering for insulated wire. 

KoMMOiD. — See Corn Oil Substitute. 

LiNOXiN. — An insoluble oxy-compound produced by the oxi- 



94 SUBSTITUTES FOR RUBBER. 

dation of certain drying oils boiled in acetone or acetic acid, from 

which is produced an elastic mass similar to India-rubber. Of 
French origin. 

Lugo Rubber. — An artificial oxidized oil substitute that orig- 
inated with a German chemist, Dr. Lugo, who introduced it into 
the United States, where it once had a large sale. It was black, 
of about the same specific gravity as India-rubber, and made, in 
connection with rubber, excellent mold work. It is not now on 
the market. 

Maponite. — A substitute for India-rubber and Gutta-percha, 
claimed to be capable of use in the manufacture of golf balls, 
tobacco pouches, etc. It is said to be vulcanizable at 260° F. An 
English patent has been applied for, the inventor being F. E. Mac- 
Mahon. 

Nigrum Elasticum. — A sulphurized oil substance appa- 
rently made from linseed oil. Very dark colored and quite hard. 
Of English origin. 

Novelty Rubber. — An English substitute invented by David 
Lang. It is made red and drab in color. It comes in small slabs 
about 18 inches square and 2 inches thick, weighing about 7 
pounds. It is said to be easily mixed with ordinary rubber, vul- 
canized in the usual way, the price being about the same as for 
reclaimed rubber. 

OxoLiN. — An English invention patented by Charles J. 
Grist, an electrical engineer, and identical with 'Terchoid'' in the 
United States. This gum is used for waterproof sheeting, print- 
ers' blankets, packings, etc. It is made of a solution of partially 
oxidized oil by adding litharge and heating to over 400° F. 
Jute, or other fibers, is then dipped in the oil, the surplus oil is 
removed in a hydro-extractor, and the oil remaining on the fibers 
is oxidized by a current of air. These operations are repeated 
twice. The material is then ground with sulphur and coloring 
matters, and treated like India-rubber. 

Parkesine. — Made from a compound of linseed oil and py- 
roxyline, and used in the manufacture of small articles that are 
sometimes made of hard rubber. A Parkesine compound for 
molding, proofing, etc., is as follows: To 500 pounds water add 
50 pounds sulphuric acid, and steep in it as much cotton, or rags, 



PARKESINE—PURCELLITE. 95 

or jute, or linen as the liquor will moisten, for 3 or 4 hours. Take 
out, drain, and expose the mass to steam heat of about 280° F., 
for an hour, if cotton or jute fiber has been used, and 3 hours if 
flax. Neutralize the acid pulp with a bath of water and soda, 
using 4 pounds of carbonate of soda to every 200 pounds of rags. 
Wash and press, pass through a coarse sieve of 12 meshes per inch, 
and dry. Grind the granulated material and sift it through a sieve 
of 120 meshes to the inch. The resulting powder may be mixed, 
in all proportions up to equal parts, with fresh rubber. Com- 
pounding 25 to 50 parts dry Parkesine, with 50 parts alcoholic 
solvent. A proofing compound is : i pound paraffine, linseed oil, 
or other drying oil ; 4 to 8 ounces Parkesine. 

Perchoid. — See Oxolin. 

Peroxide Substitutes. — Peroxide of lead having been rec- 
ommended as a better drier than other oxides used in connection 
with all compounds, the following formulas are given : 25 parts of 
walnut oil, 62 parts linseed oil, 5.5 parts peroxide of lead, 7.5 parts 
sulphur. One of greater toughness is composed of 25 parts wal- 
nut oil, 56 parts linseed oil, 5 parts peroxide of lead, 6 parts sul- 
phur, 6 parts gum juniper. [Prof. W. L,ascelles-Scott.] 

PiCKEUM Substitute. — This is made by the following treat- 
ment of Pickeum gum : 

A. 

Boiled linseed oil 160 pounds. 

Vaseline 20 pounds. 

Bastard gum (or Pickeum gum) from Central America, 

cut fine 40 pounds. 

Stir and heat to 250° to 300° F., until the gum is dissolved. 
Then cool to 100° F., and strain. 

B. 

[ Solution as above 5 gallons. 

Mixture of -l Protocliloride of sulphur 9 pounds. 

( Bisulphide of carbon 9 pounds. 

After the chemical action takes place, the mass is granulated 
and the grains are washed and stored for use, or the material may 
be masticated in a rubber mill and run into sheets for use. 

PuRCELLiTE. — The invention of Dr. C. Purcell Taylor, of 
England. An insulating substance somewhat similar to Gutta- 



96 SUBSTITUTES FOR RUBBER. 

percha,, but costing much less. It is said to be very tough and 
elastic, may be made of any color, and is either flexible or rigid. 
The specific gravity of the material is 1.2. It can be molded or 
vulcanized like India-rubber. Its insulation resistance is equal 
to that of Gutta-percha. It is unaffected by atmosphere, by alka- 
line or acid liquids, freezing mixtures and the like. 

Resinolines. — Substances so called by Eugene Cadoret, of 
Paris, who obtains them by saponifying various oils by the use 
of a metallic carbonate, using by preference carbonate of lead, 
then decomposing by nitric acid, decanting, and saturating with 
an alkali. The soap thus formed is treated with acid to form a 
resinoid body, purified by dissolving in alcohol, and evaporating 
the solution. Resinolines thus formed are very similar to natural 
resins. They are either semi-fluid, pasty, or solid. When solid, 
they are remarkable for their flexibility. 

Rosaline. — A vegetable product said to contain about the 
same chemical elements as India-rubber, and of about the same 
specific gravity. Manufactured in United States, France, and 
England. A strong point is made by the manufacturers that after 
vulcanization no chemist is able to detect that there is anything 
but pure rubber in a mixture containing 25 per cent, of Rosaline 
and 75 per cent, of India-rubber. In vulcanizing, it requires about 
one-third more time to bring about the usual result. 

RuBERiNE. — An American rubber-like solution used as an 
insulating paint, and also as a proofing mixture, and partaking of 
many of the qualities of ruberoid. It is also manufactured in 
Germany. 

Ruberoid. — An American substitute for India-rubber that 
has the physical appearance of a high grade of black oil substi- 
tute. In use, however, it differs from many of them, for the rea- 
son that it has been found useful in vulcanite compounds, while 
at the same time it may be used in ordinary soft rubber work. 

RuBBERiTE. — An artificial rubber of the same specific gravity 

as fine Para. In color, elasticity, capability for vulcanization, and 

durability, it is said to resemble the higher grades of rubber. It 

is the invention of H. C. B. Graves, London, and is made up as 

follows : 

Trinidad asphalt 47 to 80 per cent. 

Oxidized oil 20 to 30 per cent. 



RUBBERAID—TEXTILOID. 97 

Vaseline 5 per cent. 

Sulphur 15 per cent. 

Chloride of sulphur 3 per cent. 

RuBBERAiD. — An amber colored substitute manufactured 
from cottonseed oil by a secret process, which removes what the 
inventor calls the grease, leaving an elastic semi-solid which has 
been used quite largely in compounding. 

Russian Substitute. — Manufactured from the skins of rab- 
bits and other small animals, or the waste therefrom, digested in 
crude glycerine, and a little water. The formula is 3 parts by 
weight of the cleansed substance melted in water, with 3 parts by 
weight of crude glycerine, to which is added ^ part by weight of a 
concentrated solution of potassium chromate. The resultant mass 
is flexible. To make it harder, a little less glycerine and more 
chromate of potash are required. To withstand acids, 30 per 
cent, of gum lac dissolved in alcohol is added. For waterproofing 
fabrics, ^ part by weight of oxgall is added, with enough salt 
water to give it the consistency of oil. 

Soap Substitutes. — These have been exploited and explain- 
ed more thoroughly by Prof. W. Lascelles-Scott than by any- 
body else. The typical formulas that he gives are as follows : 28 
parts of aluminum soap, 60 parts of linseed oil, 8 parts of acid free 
sulphur, 4 parts of oil of turpentine. Another, to use in connec- 
tion with reclaimed rubber, is 15 parts of aluminum soap, 25 parts 
of devulcanized rubber, 60 parts fresh rubber, benzine quantum 
suMcit. Another still, in which a low grade pseudo gutta is used, 
is 15 parts aluminum soap, 25 parts Almadina gum, 5 parts raw 
rubber, 6 parts sulphur, and 4 parts oleum succini. 

Textiloid. — A mixture of a resinoline [as described by Cad- 
oret under that heading] with natural resins, cellulose, nitric cellu- 
lose, or organic substances of animal origin. The resultant mate- 
rial may be transparent, white, or colored. It is practically unin- 
flammable, has no smell, is very elastic, and, if submitted to heat, 
softens, and can be easily drawn out into fine threads. It can be 
used for waterproofing and in various other ways is a good sub- 
stitute for India-rubber. It is flexible and elastic. Textiloid is 
made of 4 parts resinoline, 2 parts nitric cellulose, and i part cam- 
phor dissolved in alcohol at 90° F. The result thus formed may 
be made in colors by the addition of metallic oxides. 



98 SUBSTITUTES FOR RUBBER. 

ToNG Oil Substitutes. — Manufactured from the Chinese 
oil known as tong oil, or wood oil. The oil is heated without any 
foreign matter being added to it, at a temperature of 250° C, 
when it becomes solidified. It is then pulverized, and impregnated 
with petroleum, which swells it, and renders it more easily 
worked. Patented by Dr. Charles Repin, Paris. 

Turpentine Rubber. — Manufactured by passing spirits of 
turpentine through a heated tube so as to vaporize it, and mixing 
the vapor with hydrochloric or other acid, so as condense and 
solidify all of the vapor. Patented by A. F. St. George, England. 

Tremenol. — A German invention that has reference to the 
production of sulphonic acids, sulphones, oils, resin oils, mineral 
waxes, etc. Results from a treatment of mineral matter with fum- 
ing sulphuric acids at ordinary temperatures, or with concentra- 
ted sulphuric acid at 120° C. The invention further calls for the 
treating similarly of the bodies obtained from the oil in their pre- 
cipitation by means of sulphuric acid. The products are then 
washed in brine and water. The inventors precipitate glue and 
gelatine from a slightly acid solution, as elastic rubber-like sub- 
stances that can be drawn into threads with perfect ease. 

VoLTiT. — The base of this is glue or gelatine prepared from 
scraps of kid skins, which are treated until they reach a gelatinous 
mass, which is filtered and mixed with oleic acid, such as is used 
in candle factories, the proportion being 80 parts of oleic acid to 
20 parts of the gelatine. The mixture is boiled for ^ hour, and 
then II parts of caustic potash solution (in 50 parts of water) is 
added. The boiling is then continued for an hour, and a special 
mass is formed to which is added resin oil, oxidized linseed oil, 
and parafifine. The whole mixture is then boiled 4 to 5 hours. 
Also spelled Voltite. It is of French origin. 

Volenite. — A substitute for India-rubber and Gutta-percha 
invented by Frederick Lamplough, United States. The compound 
is said to be a mixture of resins, or resin oil conveyed into a mass 
of fibrous material by a suitable non-oxidizable oil. This latter 
oil is used simply as a vehicle to carry the resin to its place, the 
process being completed by the distillation of the non-oxidizable 
oil, and the oxidizing of the rest of the mass. The oil used is 
preferably a fish oil, which is refined carefully before use. After 



HARD RUBBER SUBSTITUTES. 99 

saturation and treatment the vegetable fiber is changed into a 
homogeneous mass which has many of the characteristics of vul- 
canite. A formula that is said to have worked well is 10 parts by 
weight of fiber, 5 parts resin, 4 parts resin oil, 2 parts fish oil, 
treated at a temperature of 130° C, for 4^ hours. 

Waterproof Glue. — A substitute for canvas proofing made 
as follows : Dissolve 16 ounces of glue in 3 pints of skim milk, and 
to increase its strength add a little powdered lime. 

WiNTHROP Gum. — Another name for Rubberaid. 

II. SUBSTITUTES FOR HARD RUBBER AND GUTTA-PERCHA. 

Hard Rubber in its best estate is so valuable and perfect a 
product that it would always have the preference were it not for 
its unavoidable high cost. Because of this cost there are many 
substitutes for it that counterfeit it in texture, color, and quality, 
but are never quite its equal in all these points of excellence. 
These substitutes are made of cellulose, gums, and animal, vege- 
table, and earthy matters, having a variety of distinctive names 
and varied uses. To the popular mind, if they look like ebonite, 
they are hard rubber. In the same way. Gutta-percha is often 
confounded with hard rubber, which it resembles under many 
conditions. The following list covers not only certain widely- 
known compounds of hard rubber and Gutta-percha, but a num- 
ber of substitutes for them now put to many uses, the chief of 
which, perhaps, is insulation : 

Alexite. — An American insulating material which can be 
molded in any shape, is waterproof, fireproof, and acid proof, and 
can be produced in any color. In texture and general appearance 
it resembles vulcanite. 

Ambroin. — A German substitute for hard rubber, consisting 
of fiber, silica, and resin compressed to a mass. Its color varies 
from light brown to green or black. Nitric and acetic acids do 
not effect it, and even aqua regia does not injure it. Under a 
moderate heat it softens slightly and can be worked, like vulcanite, 
in a mold. It also takes a bright finish from the buffing wheel. 

Armalac. — See Insulac. 

Artificial Whalebone. — A well-known product made as 
follows: India-rubber 20 parts, sulphur 5 parts, shellac 4 parts, 



loo HARD RUBBER SUBSTITUTES. 

magnesia 4 parts, and gold brimstone 5 parts. Vulcanized some- 
what the same as hard rubber. 

Balenite, as the name signifies, is intended as a substitute 
for whalebone. It is quite elastic; in other words, it is neither 
hard nor soft, but may be characterized as semi-hard. A well- 
known compound for this is India-rubber 100 parts, shellac 20 
parts, burned magnesia, 20 parts, sulphur 25 parts, and orpiment 
20 parts. (Hoffer.) 

BiTiTE. — An English insulating material which is said to be 
bitumen refined to absolute purity and vulcanized. It is used on 
cables, in underground work, for low pressure resistance, and in 
rare instances for high pressure. 

Brooksite. — A compound of resin and heavy resin oils for 
insulating purposes. 

Caoutchouc Aluta. — A composition used as a substitute 
for hard rubber, made of leather scraps boiled in water, with a 
sufficient quantity of oxalic acid to dissolve them, and a portion 
of glue. To this are added resin, pitch, beeswax, and copal gum, 
dissolved in oil. India-rubber boiled in linseed oil is then added 
and a powder formed of plaster of paris, and a coloring matter is 
J stirred into the composition to thicken and stiffen it. 
>%A'^-'€-*-t^ Chatterton's Compound. — A widely-known compound 
sold the world over for connections for joint sheets and for unit- 
ing Gutta-percha parts, and also used for cementing Gutta-percha 
to wood. It softens readily at 100° F., and becomes firm again 
when cold. Its specific gravity is about 1.02. The best compound 
is I part by weight of Stockholm tar, i part resin, and 3 parts 
cleansed Gutta-percha, melted and mixed. 

Coralite. — A name for vulcanite which is colored to imitate 
coral. 

Cornite. — A specially hard vulcanite or hard rubber, so 
named from the Latin cornu (a horn). 

DiATiTE. — A combination of diatomaceous earth, and shellac, 
made under very heavy pressure. It may be made of any color, 
and is used as a substitute for hard rubber. 

Electrose. — A substitute for hard rubber for which the fol- 
lowing advantages are claimed: It will not tarnish metal, as no 
sulphur is used in its vulcanization ; it is cheaper than hard rub- 



ELECTROSE—ISOLATINE. loi 

ber ; it possesses high insulation properties ; it can be melted rea- 
dily into any shape, or made of any color; it does not fade; it 
possesses great strength, and takes a high polish; changes of 
temperature do not affect it; and it withstands the weaker acids 
and alkalies. 

EsBENiTE. — Made of pure cellulose, chemically incorporated 
with mica in the form of jEine powder, with the addition of mag- 
nesia and silicate, thus forming strong and close grained artificial 
mica. It is flexible, and can be molded into any shape. Esbenite 
is waterproof, does not burn readily, and is thoroughly airproof. 
Manufactured in England. 

FiBRONE. — A substitute for hard rubber which is a good non- 
conductor, waterproof, and can be handled in a lathe like vulcan- 
ite. It is said to be durable, does not contract or expand, and is 
made in all colors. It is used for thumbscrews, pushbuttons, etc. 
Plasticon is similar to Fibrone, but heavier and of a more stony 
nature, and probably made of the same material. 

Hyaline. — Made of a mixture of equal parts of gun cotton 
and a variety of resins. The gun cotton is dissolved in ether and 
the resins in solution are added, the result being a thick, gelatin- 
ous mass. When allowed to dry, this mass soon hardens and 
forms a horny, incombustible material. Invented by Frederick 
Eckstein, Vienna. 

Insullac. — A spirit copal resin varnish, with the acids of 
the resins neutralized as much as possible, to prevent the resin 
acids from attacking the copper wire. It is a transparent elastic 
material, and is superior to shellac. Armalac is made of black 
paraffine wax, in solution in petroleum. It remains permanently 
plastic under heat, although it dries quickly and thoroughly. 
Manufactured in the United States. 

Insolacit. — An insulating material produced either as a 
liquid, semi-liquid, or solid. It is not inflammable or affected by 
the most corrosive acids, alkalies, saline substances, etc. It is a 
German product and the compound remains a secret. 

IsoLATiNE. — An American insulating material prepared 
especially for high resistances. It is said to be very flexible, not 
to be affected by cold or heat unless the latter is artificial, and 
to be very durable. It is also said to protect metal. 



I03 HARD RUBBER SUBSTITUTES. 

Kiel Compounds. — One of these well-known compositions 
consists of India-rubber, sulphur, pumice stone, oil, and beeswax. 
The resultant compound makes a hard rubber, said to possess a 
superior elasticity and toughness, and capable of being- vulcanized 
in sheets at least 2^ inches thick. This compound is not affected 
by the most intense cold, and will stand a higher temperature than 
ordinary rubber. It also burns with difficulty. Its ingredients 
are said to mix faster and more uniformly than those of other 
compounds. It resists acids, and other corrosive substances, is a 
perfect insulating material, and is cheap. Another Kiel compound 
is made of India-rubber, sulphur, and mineral oil. The resultant 
compound is more flexible than ordinary hard rubber, and when 
warm is more plastic than such compounds. It is also less brittle 
and cheaper, and can be turned in a lathe with greater facility and 
less injury to the tools. 

Keratite. — Another name for hard rubber, derived from the 
Greek word meaning horn. 

Keratol. — An American waterproof preparation, not of the 
nature of rubber, but probably one of the cellulose substitutes. It 
is a colorless transparent substance, and when applied to fabrics 
renders them waterproof and prevents crocking and fading. It 
also strengthens the fabric, and allows stains to be washed off. An 
artificial leather is also made of Keratol. The name is adapted 
from the Greek word keros, meaning hornlike. Invented by Par- 
ker R. Bradley, United States. 

Lamina Fiber. — An American invention, used chiefly for 
electrical purposes. It is of various colors, heavier than vulcan- 
ized rubber, and swells to nearly double its weight when placed 
in water. It is probably a cellulose compound containing no 
rubber. 

Lactitis. — An artificial ivory made from milk, the process 
being coagulation, strainmg, and rejection of the whey. Ten 
pounds of the curd are then taken and mixed with the solution of 
3 pounds of borax in 3 quarts of water. The mixture is then placed 
in a vessel over slow fire and left until it separates into two parts, 
one as thin as water, the other resembling melted gelatine. The 
watery part is drawn off, and to the residue is added a solution of 
I pound of mineral salt in 3 pints of water. (Sugar of lead 



LA CTITIS—PLASTITE. 



103 



answers very well as the mineral salt.) This brings about another 
separation of the mass, into a liquid and a mushy solid. The liquid 
is strained or filtered off, and at this point coloring matter may 
be added. The solid is now subjected to heavy pressure in molds 
of any shape, and afterwards dried under great heat. The result- 
ing product may be used in the manufacture of billard balls, knife 
handles, or anything for which ebonite or celluloid is adapted. 

Leatheroid. — A mixture of American origin, made in black, 
red and gray, and similar to vulcanized fiber. It is insoluble in 
ordinary solvents, uninjured by alcohol, ether, ammonia, turpen- 
tine, naphtha, or other oils, is very tough, is a good insulator, and 
is of low cost. 

Marloid. — An insulating material said to be made from the 
hides of certain animals, treated by a chemical process, making it 
so hard that it can be handled in every way the same as ebonite. 
It may be transparent or opaque, and is capable of receiving a very 
high polish. It is said to give an insulation of 2,000 megohms, 
is uninflammable, and is of English origin. 

MiCANiTE. — Mica cemented together under pressure with an 
India-rubber compound. Manufactured in America. 

NiGRiTE. — An insulating compound consisting of a mixture 
of India-rubber and ozocerite. 

Pegamoid. — This, although covered by several patents, is 
said also to involve certain secret processes. In a general way, 
however, the substance is prepared by treating a fine grade of eel ■ 
lulose with a mixture of sulphuric or nitric acid to form nitro- 
cellulose or gun cotton, which is then dissolved in a suitable 
alcohol. The Pegamoid patents call for the addition of glycerine, 
sweet or olive oil, and various coloring matters. 

Plasticon. — See Fibrone. 

Plastite. — A vulcanite which is made extra hard and is 
not possessed of any special amount of elasticity. The stock 
recipe for this is : India-rubber 100 parts, sulphur 25 parts, mag- 
nesia 50 parts, orpiment 50 parts, coal tar asphaltum 60 parts. It 
is very hard and solid, and takes a high degree of smoothness and 
polish. (Hoffer.) 

Potato Celluloid. — An Austrian invention relating to an 
artificial solid produced from potatoes boiled 36 hours in a fluid 



I04 HARD RUBBER SUBSTITUTES. 

containing 8 parts of sulphuric acid and loo parts of water, and 
then dried. Pipe bowls made from it for the French market are 
said to be hardly distinguishable from real meerschaum. Billiard 
balls are also said to be made from it. 

Presspahm. — An English insulating material made from 
wood fiber so treated that it can be run through rolls into sheets 
of varying thicknesses. It is said to be capable of withstanding 
high temperatures, and is used not only in connection with elec- 
trical machinery, but also for bookbinding and for putting a finish 
on cloth. 

Sorel's Compound. — A so-called substitute for Gutta-percha 
consisting of 2 parts resin, 2 parts asphaltum, 8 parts resin oil, 6 
parts slaked lime, 3 parts water, 10 parts potter's clay, and 12 
parts Gutta-percha. Five per cent, of stearic acid is sometimes 
added. 

Stabilit. — A German invention, the compound for which is 
a secret, designed to be half way between hard rubber and vul- 
canized fiber. It is not affected by corroding substances, and does 
not absorb moisture. It withstands boiling water where hard rub- 
ber and vulcanized fiber do not, and is not attacked by muriatic 
acid or sulphuric acid. 

Vegetaline. — Cellulose treated with sulphuric acid, dried 
and ground, and then treated with resinate of soda. 

Viscose. — An English cellulose product that promises much 
a substitute for vulcanite. It may be of any color or any degree 
of hardness. It has been used in connection with rubber experi- 
mentally with excellent results. As a friction for belting it is 
said to be excellent, whether or not the belt has the regulation 
rubber cover. 

ViscoiD. — A compound of viscose, formed by mixing with it 
hot bituminous matter such as tar, pitch dissolved in coal tar, or 
the like. The resultant mixture, when solidified, constitutes a mate- 
rial of a high insulating character, and is produced at low cost. 
The bituminous and cellulose matter may be mixed in equal pro- 
portions, although there is a wide range of compounds that may 
be made through the use of various proportions of the substances. 

ViTRiTF. — A jet black, perfectly hard material, having a 
smooth polished appearance similar to ebonite. It is not aflFected 



MISCELLANEOUS SUBSTITUTES. 105 

by dampness or acids. It is a good insulator, is of low cost, and 
easily worked. 

VuLCABESTON. — This is a composition of asbestos and India- 
rubber, forming a product which is a non-conductor of electricity 
and stands the severest tests, resisting heat wonderfully. Invented 
by R. N. Pratt, United States. 

Vulcanized Fiber. — This material, which is very largely 
used, is made of cotton paper pulp, chemically dissolved, and solid- 
ified under enormous pressure. It is unattacked by ordinary sol- 
vents such as alcohol, turpentine, ammonia, etc. It appears on 
the market in two forms — hard and flexible. The hard fiber 
resembles horn and is exceedingly tough and strong, while the 
flexible fiber has the appearance of a very close grained leather. 
It is an insulator in dry places, but, as it will absorb moisture, 
it is useless in places requiring waterproof qualities. It is made 
in three colors — black, red, and gray. Vulcanized fiber is unaf- 
fected by oils or fats, and will stand action of hot grease. Low 
grades have been found adulterated with chloride of zinc and 
calcium, to the extent of nearly 50 per cent, of its weight. 

WiLLOUGHBY Smith^s Gutta-percha. — Gutta-pcrcha refin- 
ed by a special process invented by Willoughby Smith. Valued in 
England as giving an increased speed over electrical conductors 
insulated with it. 

Wray's Compound. — A composition of India-rubber, silicia, 
powdered alum, and Gutta-percha. Used in climates too hot for 
Gutta-percha by itself. It is easily attacked by seawater. 

III. MISCELLANEOUS SUBSTITUTES AND COMPOUNDS. 

"Apo Elastikon Hyphasma."' — An English formula for this 
IS : Take caoutchouc and grind it with a portion of residue from 
cottonseed oil. Work in as much vegetable fiber as will convert it 
into a strong felt, adding as much farinaceous matter as will fit it 
for the finishing roller. The outside husk from rice, finely ground, 
is preferable. Stearine pitch may be added to give a greater stiff- 
ness ; also chalk and steatite may be used to harden it. 

AsBESTONiT. — An asbestos product manufactured in Eng- 
land under a secret process, for use as steam or hot water packing. 

AsTRiCTUM. — A compound to be used in damp places, con- 



io6 MISCELLANEOUS SUBSTITUTES. 

sisting of pulped cotton 15 pounds, pitch 25 pounds, asphalt 20 
pounds, ground granite rock 20 pounds, bitumen 5 pounds, resin 
10 pounds, coal tar 12 pounds, and mastic 5 pounds. 

Caoutchite. — Vulcanized rubber exposed to heat (250° F.) 
for several days and devulcanized and recovered by this means 
alone. 

Cork Leather. — A French invention composed of thin sheets 
of cork, covered on both sides with an extremely thin India-rubber 
skin, and of a textile fabric outside. It is very light, is a good 
insulator against heat, and is waterproof. 

Dermatine. — A well known substitute for India-rubber and 
leather, made of an artificial Gutta-percha called "gum percha," 
7 pounds; powdered waste rubber, 7 pounds; India-rubber, 14 
pounds ; sulphide of antimony, 6 pounds ; peroxide of iron, 2 
pounds; flour of sulphur, 2 pounds 8 ounces; alum, 4 pounds 8 
ounces ; asbestos, powder, 8 pounds ; sulphuret of zinc, 3 pounds ; 
carbonate of magnesia, 7 pounds. A little change in this com- 
pound adapts it for machine belts. A variety of colors is gained 
by mixing in various pigments in place of sulphuret of antimony 
or peroxide of iron. The invention is patented by Maximilian 
Zingler, of London. It is claimed that Dermatine will stand more 
wear than either leather or rubber, that it is absolutely unaffected 
by heat, cold, dryness, or moisture ; and that it will stand perfectly 
the action of grease, oils, or acids. Adaptations of the formula 
given above permit it to be manufactured in molded forms. It is 
used for valves, packing, etc., and also for covering insulated wire. 

Durate. — An artificial rubber compound said to be similar 
to Dermatine. 

Fibrine-Christia Gum is manufactured just as Christia 
gum is, except that silk fibers are used in the place of hemp. 

Frost Rubber. — Another name for what is practically sponge 
rubber made from any ordinary unvulcanized rubber compound 
by the addition of a little alum or carbonate of ammonia. 

Heveenoid. — This is claimed to be more insoluble, durable, 
and pliable than almost any other rubber composition. Soft He- 
veenoid consists of India-rubber 32 parts, camphor 32 parts, lime 
I part, and sulphur 8 parts. Hard Heveenoid is made of India- 
rubber 6 parts, camphor 4 parts, glycerine i part, and sulphur 16 



HEVEENOID—LIMEITE. 107 

parts. Heveenoid is the invention of Henry Gerner, of New 
York, and is patented in the United States and Europe. Kauri 
gum is also used in certain Heveenoid compositions. One special 
advantage claimed as to the use of camphor is that the chemical 
compound termed sulphide of camphor is produced, and there- 
fore the rubber does not bloom. 

Heveenite.— Another name for Heveenoid. 

India-rubber Leather. — A compound produced by Nelson 
Goodyear in which iibrous substances were mixed with India- 
rubber to form a body the surface of which resembles leather. 

Kamptulicon. — An India-rubber compound for floor cover- 
ings. The simplest English formula is a vegetable fibrous material 
ground into a coarse powder, mixed with India-rubber, and treated 
with a cheap solvent, such as coal tar or naphtha. Coloring mat- 
ters are added, if desired. Another Kamptulicon compound is : 
Gutta-percha, cheap grade, 6 pounds; reclaimed rubber, 12 
pounds ; residuum from distilling palm oil, 6 pounds ; ground cork, 
4 pounds; ground chalk, 2 pounds; sulphur, 6 pounds; hair, i 
pound ; oxide of zinc, i pound. 

Kirrage Compound. — A well-known English patented com- 
pound, which takes its name from the inventor. It comes in two 
forms. The first, to be used not over 200° F., is composed of 
India-rubber 12 pounds, Gutta-percha 4 pounds, Stockholm tar 
25 pounds, chalk 60 pounds, hemp 4 pounds, and sulphur 10 
pounds. The same inventor also recommends the following, to 
withstand a great heat and pressure : India-rubber 20 pounds, tar 
25 pounds, coke, finely powdered, 25 pounds; Stourbridge clay 
25 pounds, sulphur 10 pounds, fine emery 25 pounds, and steel 
filings 5 pounds. 

Leatherine is a compound that closely approaches Derma- 
tine, and in fact is a part of the first patent on that product. It 
is intended as a substitute for leather cloth and is made as follows : 
India-rubber 28 pounds, substitute 10 pounds, sulphuret of anti- 
mony 13 pounds, peroxide of iron 4 pounds, sulphur 3 pounds, 
sulphuret of zinc 10 pounds, carbonate of magnesia 23 pounds, 
and sulphate baryta 8 pounds. 

LiMEiTE. — A cement that is manufactured from melted In- 
dia-rubber, with the addition of 8 per cent, of tallow, with sufii- 



io8 MISCELLANEOUS SUBSTITUTES. 

cient slaked lime to give it the consistency of soft paste. The ad- 
dition of 20 per cent, of vermilion causes the mass to harden 
immediately . 

Madanite. — A binding material for smooth surfaces, such 
as air-pumps, etc., made of 2 parts by weight of vaseline, and i 
part India-rubber; melted. This mixture may be left for years 
without perceptible alteration. A low grade gum used in the 
same way in connection with vaseline makes an excellent insulat- 
ing tape, and has also been used as a friction gum. 

Metalined Rubber. — A name used for compounds used in 
dental work, under a process patented by C. S. Leadbetter, Man- 
chester, England, for strengthening the gum with a metallic 
fabric, \^'Oven or knit. 

MoROCCOLiNE. — An imitation leather made from a secret 
compound which presumably has India-rubber for its base. Made 
in various colors but chiefly as an imitation of Morocco leather. 
An American product. 

Okonite. — A well-known compound for insulating wires and 
cables. According to an English analyist, it consists of India- 
rubber, 49.6 per cent.; sulphur, 5.3 per cent.; lamp black, 3.2 per 
cent. ; zinc oxide, 15.5 per cent. ; litharge, 26.3 per cent. ; and silica, 
0.1 per cent. 

Pantasote. — A secret compound, probably of oxidized oil, 
which is used for the manufacture of artificial leather coverings 
for furniture, bookbindings, etc. 

Pedryoid. — A rubber-like finish for cloth, made presumably 
of oil, in tan, brown, olive, and other colors, and used chiefly in 
shoe finishing. 

Rathite. — A mixture in which waste silk fibers are incor- 
porated with India-rubber to impart resiliency and durability. 
About 6 ounces of silk are used with 28 pounds of rubber com- 
pound. It is employed in making tires, pump valves, packings, 
etc. Patented by A. I. Rath, Cheshire, England. 

RuBBERic. — Fiber blended with India-rubber in solution, 
stretched, and dried. Used chiefly in making rubber tires and me- 
chanical rubber goods. Patented by William Golding, Manches- 
ter, England. 

Rubber Velvet. — Manufactured by sprinkling powdered felt 



RECLAIMED RUBBER. 109 

of a variety of colors over proofed cloth before vulcanization. The 
result is a velvet-like fabric, elastic and waterproof. 

Theskelon Cement. — A metalic substance used for water- 
proofing and for certain kinds of packings. It will neither ex- 
pand, contract, nor rust. It is used instead of wax for sealing 
purposes, and resists acids, alkalies, and grease. It is often used 
in place of asphaltum. It can be mixed with tar, pitch, asphal- 
tum, and other similar ingredients, the compound possessing ex- 
traordinary adhesive power. Patented by Thomas Smith, London. 

Vulcanine. — A mixture of India-rubber, asbestos, litharge, 
lime, and powdered zinc, to which is added a percentage of sul- 
phur. Mentioned in a patent granted to J. E. Hopkinson, West 
Drayton, England. 

Whaleite. — See Woodite. 

WooDiTE. — A name suggested by Sir E. J. Reed for an India- 
rubber compound invented by Mrs. A. M. Wood. It is said to 
possess the elasticity of India-rubber, to be uninflammable, and not 
injured by salt water. It is used in making valves, packings, etc. 
It is claimed that it will not become sticky or soft under heat or 
steam pressure, and will stand hot grease and other lubricants, and 
neither acids, alkalies, nor wastes from oil refineries, distilleries, 
etc., affect it in the least. A compound for Woodite or Whaleite 
packing is : Asbestos fiber 38 pounds, asbestos powden 38 pounds, 
earth wax 6 pounds, charcoal finely ground 9 pounds, ground 
whalebone 20 pounds. Para rubber 80 pounds, and sulphur 5 
pounds. 

IV. RECLAIMED RUBBER. 

Reclaimed rubber, known also as recovered rubber, shoddy, 
and crumb, is produced from worn-out rubber goods. There are 
two methods in vogue, known respectively as the mechanical and 
the chemical processes. The most satisfactory reclaimed rubber 
is made from old rubber shoes. Where the mechanical process is 
followed, the rubbers are ground to a fine powder, which is run 
over magnets to extract the iron, and is then put through a blow- 
mg process, which separates and woolen or cotton fibers from the 
rubber. The rubber powder in then subjected to a high degree 
of heat (the process known as devulcanization), and afterwards 



no RECLAIMED RUBBER. 

sheeted, when it is very similar to unvulcanized compounded 
rubber. 

The chemical process is very similar to the mechanical, ex- 
cept that the fiber is destroyed by means of acid solutions and 
quite a percentage of it is washed out with the residue of the acid 
after the process is finished. Special grades of reclaimed rubber 
are made from mechanical goods that have high grade frictions in 
them and also from unvulcanized scrap. Rubber is also reclaimed 
from ordinary mechanical goods, such as hose, belting, and pack- 
ing, and for certain purposes is mixed v\^ith what is known as shoe 
shoddy. White scrap, from wringer rolls, tubing, druggists' sun- 
dries, and the like, is also produced. The great trouble with the 
white is that, on second vulcanization, it is apt to be very hard. 
At one time, hard rubber dust was to be found in the market and 
was used as a shoddy in certain grades of vulcanite. There is 
to-day but very little of it to be found, however, as most of the 
manufacturers of hard rubber goods find a use for all that they 
make. 

The processes followed in the reclaiming of waste rubber are 
no longer secret. Those who are in the business of manufactur- 
ing for the trade are able to do it as a rule because they buy vv^aste 
stock in very large quantities at a lower figure than a small user 
could, besides which, by manufacturing the goods in large quan- 
tities, they can do it more economically than it could be done in a 
small way. It is not exposing any trade secrets, therefore, if one 
briefly reviews the various processes employed. 

Almost the first attempt at recovering rubber waste was that 
done at the Beverly Rubber Works, in Massachusetts, back in the 
fifties, when Hiram L, Hall boiled waste vulcanized rubber in 
water, after reducing it to a powder, and then sheeted it. It is 
a curious fact, that in one little mill in the United States to-day, 
the manufacturer grinds his own scrap, boils it in hot water until 
it is in condition to sheet, and really makes a fair article out of it. 

The year after Hall's patent was granted, another was grant- 
ed to Francis Bashchnagel, who paved the way for devulcaniza- 
tion by covering a process whereby a finely ground rubber was 
exposed to the action of live steam. It was not, however, until 
E. H. Clapp took hold of the business and discovered a process 



PATENTED PROCESSES. iii 

for blowing the fiber out of the finely ground rubber prior to its 
devulcanization that the goods began to be used to a large extent. 

The next step in the progress of the art was characterized by 
the taking out of a great variety of patents, most of which depend 
upon various acids and alkalies for destroying the fiber. These 
patents were more than fifty in number, and were fully reviewed 
with their attendant processes in the famous suits brought by the 
Chemical Rubber Co. against The Goodyear's Metallic Rubber 
Shoe Co. and the Raymond Rubber Co. While it would be tedi- 
ous to go into that matter, it is interesting to touch upon the im- 
portant processes involved. The action of acids upon fibers, of 
course, had long been known ; in connection with the rubber busi- 
ness, however, it was without doubt novel. The Hay ward pa- 
tent, for instance, mixed 75 pounds of sulphuric acid with 8 hogs- 
heads of water, and in this way the fiber was weakened so that 
it was easily ground up with the rubber. The Faure patent called 
simply for the immersion of the clippings in an acid, which in 
disintegrating the textile matter set the India-rubber free. Hiram 
Hall advised the use of lime or alum to eat up the cloth, and also 
a solution of i part of sulphuric acid to 9 parts of water. Burg- 
hardt used muriatic acid for destroying the cloth fiber. The Hein- 
zerling patent called for a treatment first with acids, and then 
with alkalies. It is also to be remembered that Charles Goodyear 
directed that crude India-rubber should be subjected to a 10 per 
cent, solution of sulphuric acid to eat up the bark with which the 
gum might be contaminated. 

The Mitchell patents, the Bourn patents, and others, where 
an extremely dilute acid was used, and where a concentrated 
acid was called for, have been so thoroughly reviewed that those 
familiar with the rubber business know all about the processes 
employed. 

In addition to those that are now in use, a few unusual ones 
may be interesting. For example, the Torstrick process, in which 
dilute nitric acid and fusel oil were mixed with the gum in a 
heated state, or passed through it in the shape of vapors, making 
the mass sticky, after which a small quantity of chloride of cal- 
cium was added and the gum sheeted. 

Conrad Poppenhusen mixed rubber scrap with essential oils, 



112 RECLAIMED RUBBER. 

a little turpentine being used preferably, left the scrap until it had 
become soft, and then passed dry gaseous ammonia into the mass, 
forming a gelatinous viscid product. 

C. F. E. Simond mixed 2 parts of chloride of lime with 100 
parts of waste rubber, and brought it to a high degree of heat, 
by which the sulphur was volatilized, which took from 15 to 60 
minutes and then used the rubber over. 

Thomas J. Mayall mixed vegetable tar with waste rubber — 
exposed it to the heat of the sun, or to a gentle artificial heat, and 
got a soft pasty mass that he was able to work with crude rubber. 
He also invented a process for sprinkling the finely ground rub- 
ber with camphine and setting the mass afire in a partially covered 
vessel, his claim being that if the fire was stopped at a certain 
point, a tough viscid mass was the result, which contained neither 
sulphur nor fiber, and could be reworked like unvulcanized rubber. 

Beylikgy exposed vulcanized rubber for a number of days to 
a temperature of 250° F., after which he claimed that it became an 
adhesive mass, insoluble in alcohol, partially soluble in ether, and 
wholly soluble in benzole. He called this caoutchoucite and 
claimed that it could be vulcanized with the addition of sulphur 
at a lower temperature than ordinary crude rubber. 

McCartney, of Glasgow, mixed vulcanized rubber with naph- 
tha and a little acetic acid. He also added camphor, and by the 
action of heat produced in reality a rubber paint. 

These are but a few of the many processes that have been em- 
ployed, and this information, in connection with the rubber super- 
intendent's knowledge of his particular problem, may in some 
cases enable him to reduce intractable and valueless wastes to a 
condition where it can be used in the factory. 

The following are the principal grades of reclaimed rubber 
now on the market, a few manufacturers using copyrighted or 
distinctive names : 

"Eureka" rubber. — The highest grade of black reclaimed 
rubber. 

"Atalanta." — A name for a good grade of reclaimed rubber 
of Eureopean manufacture. 

"Pongo." — A name for American reclaimed rubbers when 
they are sold in the European market. 



CELLULOID AND CELLULOSE. 113 

"Excelsior." — A high grade of reclaimed rubber said to be 
made largely of unvulcanized clippings. 

"Acme." — A fine grade of American reclaimed rubber. 

"White Extract." — A good grade of white reclaimed rubber 
sold in the American market under various names. 

The reclaimed rubber that is made of old shoes is usually 
marketed in two grades only, which are "Standard" and "XXX.," 
the difference being well expressed by the price, which differs 
a cent to the pound. 

Special grades made of tires, inner tubes, air-brake hose, etc., 
are marketed, but are usually named for the kind of scrap from 
which they are taken. 

v.— CELLULOID AND CELLULOSE PRODUCTS. 

Celluloid is made in the main from camphor and nitro- 
cellulose in alcohol, ether being sometimes employed as an addi- 
tional solvent. The paste formed in this way is warmed gently, 
and then rolled out into thin sheets. The product is a brittle 
horny mass, consisting of a chemical, or at least an intimate, mix- 
ture of camphor and pyroxyline. A great variety of coloring 
matters may be added to it, and it is susceptible to manipulation 
and processes whereby it has been made quite flexible and prac- 
tically incombustible. Crude celluloid has a specific gravity vary- 
ing between 1.25 and T.45, and has a strong odor of camphor. 

Cellulose is a pure substance forming the cellular tissue of 
plants. In the arts use is made generally of cotton or filter 
paper which has been treated with acids to dissolve out impurities, 
and forms a basis for the manufacture of celluloid, gun cotton, 
pyroxoline, and xylonite. On analysis it shows: Carbon 44.44, 
hydrogen 6.18, oxygen 49.38. It is dissolved in sulphuric acid, 
and is converted into dextrine, and, by prolonging the action, into 
glucose. So far it has not been used largely in rubber compound- 
ing, but both alone and in connection with various other ingre- 
dients has been applied as a waterproofing. It is the basis of cer- 
tain Swiss puncture fluids. 

Gun Cotton. — Prepared by treating cotton wool with a mix- 
ture of strong sulphuric and nitric acids, or nitrate of potash may 
be substituted for nitric acid. After treatment with acid the gun 



114 CELLULOID AND CELLULOSE. 

cotton is rinsed carefully in cold running water, and then dried by 
pressure or by exposure to the air. All acid should be removed to 
prevent danger of explosion. Gun Cotton has been used to render 
fabrics waterproof, for varnishing India-rubber to render it im- 
pervious to gases, and in insulation work. Alexander Parkes, as 
far back as 1855, used a solution of Gun Cotton with gums or 
resins to take the place of compounds of India-rubber. He ren- 
dered Gun Cotton less inflammable by using biphosphate of am- 
monia, magnesia, talc, alum, or similar substances. As a good 
solvent for Gun Cotton, he distilled in i gallon of naphtha from 
2 to 6 pounds of chloride of calcium. Charles Macintosh used as 
a solvent equal parts of wood spirit and coal tar naphtha. 

Nitro-Cellulose, — This is produced by the action upon cel- 
lulose of nitric acid or a mixture of nitric and sulphuric acids. 
According to the length of time the acid is allowed to act, the 
resulting nitro-cellulose contains either 53.7, 43.6, 36.7, or 28 per 
cent, of nitric acid (nitric-anhydride). Gun cotton is usually a 
mixture containing a higher percentages while Pyroxyline — or as 
it is sometimes called, soluble cotton — is a mixture of a lower com- 
pounds. The solution of pyroxyline in a mixture of alcohol and 
ether is called Collodion. 

Pyroxyline. — A species of gun cotton less explosive in its 
qualities, prepared from cellulose by means of nitro-sulphuric acid. 
Its solution in a mixture of ether and alcohol is called Collodion. 

Xylonite. — See Celluloid. 



CHAPTER VII. 

RESINS, BALSAMS, GUMS, EARTH WAXES, AND GUM-LIKE SUBSTANCES- 
USED IN RUBBER COMPOUNDING. 

A GREAT variety of vegetable, mineral, and animal resins and 
waxes find uses in admixture with India-rubber and Gutta-per- 
cha. Their important uses are to render compounds adhesive, as 
in frictions, to assist in insulation, to add luster, and to modify the 
texture of the vulcanized compound. Many gums, like many 
earths, lend special virtues which they possess to rubber com- 
pounds. The more important of these materials, and those most 
generally used, are described in the following pages. 

Adamanta Resin. — An imitation copal, manufactured from 
common resin by a special hardening process. It is not soluble 
in alcohol or benzine, but completely so in boiling turpentine. It 
is free from acids and alkalies, and has the same melting point as 
Zanzibar copal. It is used rarely in rubber shoe varnish, and often 
in cheap frictions in mechanical lines, being moistened with resin 
oil to increase its adhesiveness. 

Amber. — A fossil resin chiefly found in Prussia, on the shores 
of the Baltic sea; it occurs also in Sicily and sometimes in the 
United States. It is the hardest and heaviest of the resins. Its 
specific gravity is about 1.07. By distillation a yellow oil — oleum 
succini or oil of amber — is obtained, and a yellow resin remains 
in the still. Amber varies in color from light yellow to a deep 
brownish red. It is insoluble in almost all of the ordinary sol- 
vents. When heated above its melting point, however, it becomes 
partly decomposed, and is then soluble in oil of turpentine and 
alcohol. It makes a very fine transparent varnish, which is used 
on negatives in photographing. It is used in cements for fasten- 
ing lineoleum and rubber tiling to decks, and is also mentioned in 
the formulas for certain patented gums. 

Asphalt is undoubtedly an oxidized residue from evaporated 
petroleum. This name is applied usually to the solid bitumen, the 
liquid being called mineral tar, and sometimes maltha. It is chiefly 
made up of hydrocarbons, but contains a certain amount of sul- 
phur and nitrogenous bodies. It is known also as natural pitch, 

115 



ii6 GUMS AND BALSAMS. 

Jews' pitch, asphaltum, bitumen, etc. It is a black hard substance 
which, when freshly broken, shows shining surfaces that are 
always correspondingly rounding and hollowing. It is insoluble 
in water and alcohol, but dissolves in benzine, acetone, and carbon 
disulphide. Is used in rubber compounding in place of coal tar, 
and in insulating compositions, and in certain substitutes like Ke- 
rite. Commercially there are two grades, known as "lake pitch" 
and "land pitch,'' of which the latter is the harder. 

In solution it is used sometimes to protect rubber goods that 
are exposed to the destructive influence of brine. A little Asphalt 
is also said to increase the elasticity of hard rubber. Asphalt mixed 
with resin and oil of tar forms a low grade artificial Gutta-percha. 
It is added to "Cooley's artificial leather" to harden it and enable 
it to resist heat. It is also the basis of one type of marine glue. 

Artificial Asphalt. — This is made by heating sulphur and 
resin together to about 250° C, where the reaction takes place, 
attended by the evolution of sulphuret and hydrogen, and leaving 
an almost black, pitchy substance resembling asphalt. It is insolu- 
ble in alcohol, but dissolves readily in benzine. 

AuvERGNE Bitumen. — A species of natural asphalt found in 
the province of Auvergne, France. It is similar to Trinidad 
asphalt, but is impure, containing clay, silica, magnesia, iron, and 
traces of arsenic. (See Asphalt.) 

Balsam. — This term is given to oleo resins which are soft at 
ordinary temperatures, and are really a mixture of such a resin 
and the essential oil of the plant from which they exude, such as 
benzoin, tolu, etc. 

Balsam of Storax. — Produced from the inner bark of a 
tree of the genus Storax, in Asia Minor. Commercially it is 
a soft, coarse, dark colored powder, or, more commonly, a semi- 
fluid, adhesive substance, brown outside, greenish gray inside. 
The sweet gum of the southern United States is allied to the East- 
ern drug, and was formerly much used in chewing gum. Used 
in general cements, being particularly good in leather cements ; 
also for glass, stone, and earthenware cements. 

Balsam of Sulphur. — A solution of sulphur in boiling vola- 
tile or olive oil. Used in certain rubber compounds as a vulcaniz- 
ing agent and a protection against blooming. 



BEESWAX— BURGUNDY PITCH. 117 

Beeswax is obtained from the comb built by honey bees. The 
crude wax is yellow and soft, with a granular fracture. Its speci- 
fic gravity varies between .965 and .969, its melting point being 
between 140° and 144° F. It is often adulterated by water, by 
white mineral powders, and by cheaper substances, such as vege- 
table wax, paraffine, etc. White wax is that which has been ex- 
posed to the sun or to the moderate action of nitric or chromic 
acid, thereby being bleached. It is sometimes used with rubber 
in medicinal plasters. Ordinary beeswax is largely used in the 
valuable hard rubber compounds known as the Kiel compounds. 
Sheet beeswax is often used in the work of vulcanite pattern mak- 
ing. It is also used in processes for making fabrics water-repel- 
lent, the other ingredients being aluminum, resin, soap, wax, and 
silicate of soda. With Gutta-percha it is an ingredient in shoe- 
makers' wax, and also in certain proofing compounds. Hancock 
used it in a Gutta-percha compound for a soft effect. In a hard 
rubber compound made up of India-rubber, sulphur, oil, and 
pumice stone, it is said to be acid proof. 

Birch-bark Tar. — A peculiar tar obtained during the dis- 
tillation of birch-bark for oil, being probably the same as Russian 
Jackten extract. Used in the manufacture of certain rubber sub- 
stitutes. 

Bitumen, — The term applied to a body made up of several 
hydrocarbons. It resembles Trinidad asphalt and is of the same 
nature. Its specific gravity is from 1.073 to 1.160. Artificially it 
is prepared from shales, mineral asphalt, etc. It is used as a source 
of paraffine. The West Indian product is known as Chapapote. 
A solution is made from it in which the tapes are soaked that are 
used for covering wire that has been insulated with India-rubber. 
Bitumen has been utilized by what is known as the calender pro- 
cess, which is a partial vulcanization, rendering it valuable as an 
insulator. 

Black Pitch. — Is the residue left after the oils of tar have 
been distilled from that body. Used in weather proofing work. 

British Gum. — See Dextrine. 

Burgundy Pitch. — Is obtained from the hardened juice or 
sap which concretes upon the bark of the Norway spruce. As 
imported it is often quite impure and should be melted and strained 



ii8 GUMS AND BALSAMS. 

before being used. It is almost entirely soluble in glacial acetic 
acid or boiling alcohol, and somewhat in cold alcohol. When pure 
it is hard and brittle, with a shining fracture, reddish or yellowish- 
brown, aromatic. It is much used in cements, in electric tape, and 
in the manufacture of porous plasters. Common resin is often 
melted and mixed with fats and water, forming a gum that much 
resembles Burgundy Pitch. 

BuRMiTE Amber. — Found in Burma, but quite inferior in 
quality. It is a little harder than amber proper, is easily cut, takes 
an excellent polish, but has less variety of color. (See Amber.) 

Button Lac. — See Shellac. 

Canada Balsam. — Sometimes called Canada turpentine. It 
is derived from the Abies balsamea. It is a yellowish or greenish 
transparent liquid, completely soluble in ether, chloroform, or ben- 
zol. It is sometimes called Balsam of Fir, but it does not really 
belong to the balsams, being a true turpentine. Strasburg turpen- 
tine is sometimes substituted for it commercially. It is used in 
certain compounds to prevent sulphur from efflorescing. With 
paraffine, beeswax, and coloring matters, it is used for insulating 
colored yarns that are used for anunciator and similar wires, and 
it was also used by Duncan in Gutta-percha cements for leather. 

Candle Tar. — The residual products from the distillation of 
animal fats, oils, etc., are known as candle tar. This product is 
sometimes soft and ropy, and at other times quite hard. Mixed 
with sulphur, it is said to produce a compound having some of 
the elasticity and other desirable qualities of vulcanized India- 
rubber. 

Casein (also called Caseum) is one of the chief constituents 
of milk, being that part which forms the curd of sour milk, and 
is familiar in the form of cheese. A similar substance, prepared 
from peas, beans, lentils, and the like, is called vegetable casein. 
'It is used in shower-proofing after a German formula in connec- 
tion with soda, lime, and acetate of alumina; also, in cements of 
which Gutta-percha is the base, for joining small particles of lea- 
ther, shavings, etc. 

Carnauba Wax is found in Brazil, where it forms as a coat- 
ing on the leaves of a certain palm (the Corypha cerifera), and is 
removed by pounding and shaking. It is very hard and is of a 



CERAMYL— DEXTRINE. 119 

greenish or grayish color. Its specific gravity is about 0.995, it 
is odorless, and melts at 185° F. It dissolves completely in boil- 
ing alcohol, and is used on insulated wire as a finish, and in the 
manufacture of wax varnishes. 

Carn Gum. — Used instead of ozocerite as a finish for tape 
or braids that cover insulated wire. (See Carnauba Wax.) 

Ceramyl. — A material used in the finishing process in the 
manufacture of elastic web. Its use is to make the web stronger, 
and in a measure to act as a size, causing it to lie flat. It is also 
said to add strength to it. By the application of heat, ceramyl, 
which comes in the form of a semi-solid, is reduced to a liquid. 
In English practice this is said to have driven out the use of glue 
in the dressing of elastic webs. Ceramyl is manufactured in Eng- 
land. 

Cerasin, also spelled Ceresine, is of a butter yellow color, 
odorless, and has a specific gravity of .918 to .922. It is used 
chiefly in covering anunciator wires where the object is to pre- 
serve the colors of the yarns in the braiding. (See Ozocerite.) 

Cherry Gum. — A pale yellow or red brown gum, coming 
from the bark of old cherry trees. It contains 35 per cent, of cera- 
sJne, 52 parfts of arabicum, and i to 3 per cent, of ash. This 
gum is chiefly used in the manufacture and finishing of fine felt 
hats. The gums on the market are of two qualities, the German, 
which is the best, and the Italian. It is used in insulating instead 
of purified ozocerite, in certain cases where a little more adhesive- 
ness is required. 

Coal Tar. — See Tar. 

CoLOPHANE. — See Rosin. 

Colophony. — See Rosin. 

CooRONGiTE. — The name given to a rubber-like mass found in 
Coorong, South Australia. Some place it among the fossil resins. 
Coorongite is not soluble in the ordinary solvents used in rubber 
work, but, after mixing with India-rubber, it can be put in solu- 
jtion. According to Forster, it vulcanizes somewhat as India-rub- 
"ber does. (See Pseudo Rubbers.) 

Dextrine is a sort of intermediate product between dextrose 
and starch. It is soluble in cold water, and is much used as a 
substitute for gum arable in mucilage, as it has strong adhesive 



I20 GUMS AND BALSAMS. 

properties. Cooley combined it with a little Gutta-percha, resin 
oil, and earthy matters in the production of what he called arti- 
ficial leather. It is used also in a mixture with plaster of paris, 
making a tough surface mold for small experimental rubber work. 

Dextrose is obtained from starch generally, and is crystal- 
ized glucose. It is soluble in water, and has many commercial 
uses. For example, it was used by Hancock as a sizing for cloth 
on which was spread rubber in solution, the Dextrose being there 
in order to keep the rubber from sticking to the cloth. In other 
words, this was a sort of cheap calendering process. 

Earth Wax. — See Mineral Wax. 

Elaterite is also known as elastic bitumen or mineral caout- 
chouc. It appears naturally in soft, flexible masses of a brownish 
black colors somewhat resembling India-rubber. It is composed 
of 85.5 per cent of carbon, and 13.3 per cent, of hydrogen. In its 
physical characteristics, Elaterite is found in infinite variety. It 
is sometimes elastic and so soft as to adhere to the fingers, and 
sometimes brittle and hard. One kind of it, when fresh cut, re- 
sembles fine cork both in texture and color, and will rub out pencil 
marks. Its elasticity is due to its cellular texture, and to the mois- 
ture with which it combines. It is used to a certain extent in 
insulating compounds, but is intractable and so far shows no spe- 
cial features of value above other minerals of the same series. A 
few years ago a company was formed in Colorado which claimed 
to be able to make many kinds of rubber goods from this product, 
alone, but little has been heard of the plan of late. (See Gilson- 
ite.) 

Elastic Glue is used with India-rubber and Gutta-percha in 
shoemakers' cements. (See Substitutes.) 

French Asphalte. — See Auvergne Bitumen. 

Fichtelit. — Occurs in a peat bed near Redmitz in the Fich- 
telgebirge in Germany, and also in fossil pines in the form of 
scales or flat needles. It has also been met with in Franzenbad 
and in Denmark. A hydrocarbon little known, though mentioned 
in certain patented rubber compounds. 

Fish Glue. — Made by boiling the heads, fins, and tails of 
fish by high heat. It is generally made into a liquid glue by a 
treatment with acetic or hydrochloric acid, whereby its property 



GLUES— GELATINE. 121 

of gelatinizing is lost. It would have a disagreeable odor were 
it not for the fact that that is destroyed by adding creosote or oil 
of sassafras or something of that kind. Fish Glue is used in a 
cement for cured rubber, in connection with Gutta-percha and 
rubber dissolved in bisulphide of carbon. (See Glue.) 

Garnet Lac. — See Shellac. 

GiLSONiTE. — A hydrocarbon valued for its elasticity. One of 
the purest of crude bitumens, it is mined in the Uncompahgre In- 
dian reservation, Utah, United States. It is a black, tarry-looking 
substance of brilliant luster. It is used for varnish making, in 
paints, and for insulation, either with or without rubber, one well- 
known compound consisting of rubber, linseed oil, and Gilsonite. 

Glucose. — The commercial form is prepared from starch 
usually, as that is the cheapest raw material. The starch paste 
being boiled with mineral acids, dextrose, maltose, and dextrine 
are produced. Glucose in this country is made entirely of corn- 
starch; in Europe, however, sago starch, rice, and potato starch 
are used. It is neutral, and both odorless and colorless. It is 
really a kind of sugar that is with difificulty crystalizable, and it 
is also called grape sugar. It occurs in commerce either as a thick, 
sweet, heavy liquid, or as a white solid mass. It is used with rub- 
ber glue, sugar, whiting, and glycerine in making bookbinders' 
cements, and in making puncture fluids for pneumatic tires. 

Glue. — An impure form of gelatine obtained from the horns, 
hoofs, skins, and bones of animals. Glue of good quality should 
be bright brown or brown yellow in color, free from specks, glossy, 
perfectly clear, hard, and brittle, should not become damp by ex- 
posure to the air, and should snap or break sharply when being 
bent, the fracture showing a glassy, shining appearance. Used in 
bookbinders' cements, in cheap frictions, and in cheap horse-cover 
compounds with rubber. A size made of glue was used by Brock- 
edon to protect fabrics that come in contact with the liquid used 
in cold curing. This was afterwards dissolved ofif by an alkaline 
solution. 

Glugloss Gelatine. — A gelatinous product used largely in 
Amercia in waterproofing fabrics. It is dissolved in hot water to 
use, and makes an excellent waterproof sizing. A mixture of gly- 
cerine with it increases its elasticity. It combines readily with 



122 GUMS AND BALSAMS. 

glue, dextrine, or any such products, and develops considerable 
adhesiveness. 

Gluten. — A vegetable substance obtained from wheat and 
other grains. Treated with tannic acid, it is used as a substitute 
for Gutta-percha under a formula by Johnson, who says the pro- 
duct can be vulcanized. Another formula calls for its mixture 
with oil and sulphur, as a substitute for Gutta-percha. In cements 
it is the basis of one for uniting leather scraps, and is used with a 
little Gutta-percha. 

Gum Anime is a South American fossil resin similar to 
copal. It occurs in small irregular pieces of a pale yellow color. 
Has a high melting point, and its specific gravity is 1.028 to 1.072. 
Mixed with rubber and earthy matters and dissolved in turpen- 
tine, it formed one of the early compounds for clothing. 

Gum Arabic is an exudation from a species of Acacia. It 
is made up of clear, or semi-transparent fragments, hard and brit- 
tle, breaking with a shining fracture. It is inodorous and feebly 
sweetish to the taste. Its specific gravity is 1.31 to 1.52, for dried 
gum. It comes from Africa and is known also as Acacia and Gum 
Senegal. It dissolves in hot or cold water. It is used in connec- 
tion with plaster of paris in making a tougher surface mold for 
small and experimental rubber work. Enough gum is added to 
make the mixing solution about the thickness of a thin syrup. 
It is largely used in cements. It is also used in certain shower- 
proof compounds, and in paste blackings made of caoutchouc oil, 
vinegar, molasses, and boneblack. 

Gum AMMONiAcuM.^Exclusively obtained from Persia as 
tears, or aggregated masses, of a peculiar smell and a taste slightly 
sweetish, bitter, and somewhat acrid. Its specific gravity is 1.207. 
Used in solutions for pressed leather cuttings and fibrous wastes. 
Ten parts of this gum mixed with 20 or 25 parts of Gutta-percha 
form a cement possessing both elasticity and solidity, and is tho- 
roughly waterproof, used for filling cracks in horses' hoofs. Also 
used with Gutta-percha, boiled linseed oil, and caseum or casein, 
for sticking together small particles of any dry matter in the pro- 
duction of artificial leather. 

Gum Benzoin. — Occurs in lumps of yellowish brown tears, 
stuck together and more or less mottled from the white inside the 



GUM BENZOIN— GUM DAMMAR. 123 

tears. Its specific gravity is from 1.063 to 1.092. Of an agree- 
able balsamic odor and very little taste, but irritating when 
chewed for some time. Used in linseed oil proofings, presumably 
to kill odor; also in certain Gutta-percha and India-rubber com- 
pounds for disguising the odors. Four per cent, of the weight of 
the mass is said to be sufficient to make the odor an agreeable one. 
According to Forster, a little of it mixed with Gutta-percha 
greatly improves the quality. 

Gum Asphaltum. — Refined natural bitumen, also called 
litho-carbon. Is found in Texas and at one time was exploited as 
a substitute for rubber. (See Litho-Carbon. ) 

Gum Camphor. — The white transparent substance known by 
this name is obtained from Japan and the island of Formosa. It 
is really an oxygenated essential oil. Its specific gravity is 0.985. 
Sparingly soluble in water, and very soluble in alcohol, ether, 
acetic acid, and hydrocarbons or volatile oils. Is largely used in 
the manufacture of celluloid. Gum Camphor is also used in com- 
pounds of the substitute order like Textiloid, Kerite, etc. Was 
also the basis of several remarkable compounds known as Hee- 
venoid (which see). 

Gum Copal. — Hard Copal is a fossil resin obtained from the 
East Indies, South America, and the eastern and western coasts 
of Africa. It occurs commercially in roundish, irregular pieces, 
having a specific gravity of 1.045 to 1.139. It is insoluble in 
alcohol, partially soluble in ether, and slightly so in oil of tur- 
pentine. Soft Copal is obtained from living trees in New Zealand, 
the Philippine islands, Java, and Sumatra. Used with shellac, 
asphaltum, and arsenate of potash for waterproofing leather ; also 
in cements, in proofing compounds, and in varnishes in connec- 
tion with India-rubber, lead, alum, and other ingredients dissolved 
in spirits of turpentine. 

Gum Dammar is derived from the Amboyna pine, growing 
in the Malay peninsula, Sumatra, and Borneo. The resin exudes 
in tears and is collected after it has dried. It makes a very trans- 
parent varnish, the gum being soluble in benzine, essential oils, 
and to a certain extent in alcohol. Used in artificial leather com- 
pounds, and with rubber, asphalt, and fish oil for waterproofing 
leather. It is quite largely used in rubber cements. 



124 GUMS AND BALSAMS. 

Gum Elemi comes from the Philippine islands, and is a rosin 
obtained from certain trees there. It varies from white to gray- 
in color, and is quite soft and very tough. Alcohol and other 
solvents readily dissolve it, and its ofhce usually is to give tough- 
ness to varnishes in which are harder resins. Used in connection 
with India-rubber and benzine in the production of puncture 
fluids. (See Manila Gum.) 

Gum Euphorbium appears in the market in the shape of tears 
of irregular shape, varying in size from a small pea to i^ inches 
in length. Of a dirty gray or yellowish color, and very largely 
mixed with impurities. Must not be confused with Gum Euphor- 
bia (which see.) 

Gum Frankincense. — Also called Olibanum (which see.) 

Gum Gamboge. — The best is found in commerce in cylindri- 
cal rolls of a dull orange red color. Another form is that of lumps 
or cakes. Its powder is bright yellow and its taste very acrid, but 
it has no smell. It is derived from a tree which is a native of 
Cochin China and Siam. Is used chiefly as a pigment. It is the 
basis of a general cement in which is also found rubber, alum, and 
burnt sugar, and in another is used with rubber, white lead, gum 
benzoin, alum, sugar, and sulphur, for cementing vulcanized 
rubber. 

Gum Lini. — A gum made from linseed, often used as a sub- 
stitute for gum arable. The seeds are first boiled in water for an 
hour, the resulting thick mass filtered, and then treated with twice 
its volume of 90 per cent, spirits of wine. A flocculent white 
precipitate separates, from which the dilute spirit can readily be 
decanted. The gum is clear, grey brown, fragile, and dissolves 
in water. Two grams in 30 grams of oil is almost identical with 
an emulsion of gum arable. In connection with coloring matters is 
the basis for the Knowlton patented waterproofing process. 

Gum Tragacanth is an exudation which comes in the form 
of translucent plates of a dull white, which water swells and partly 
dissolves. It is often used in mucilage in place of gum arable. 
The gum comes from the Levant from the Astragalus gummifer. 
Has been used in connection with Gutta-percha for making dental 
plates that are soft and adhesive to the membranes and that will 
not rot or deteriorate. 



GUM TRAGASOL— ISINGLASS. 125 

Gum Lac. — See Shellac. 

Gum Tragasol. — This is a gum produced from the kernels 
of the Ceratonia siliqua. The use of this gum as a solvent for 
India-rubber, Gutta-percha, or celluloid has been patented in Eng- 
land. A mixture of 25 parts of dissolved India-rubber, 75 parts 
of strong gum solution, with the addition of i part of carbolic 
acid to 500 parts of the mixture, makes a cement for wood, and 
a preservative paint against insects and vermin. 

Gum Juniper is the gum known as sandarac, obtained from 
an evergreen growing in northern Africa. It occurs in small, 
light-colored grains, with a slightly bitter taste. It is soluble in 
turpentine oil and alcohol. Is used as an assistant in making per- 
oxide substitutes. Mixed with rubber and earthy matters and 
dissolved in turpentine, it was one of the early compounds for 
clothing. 

Gum Olibanum. — The frankincense of the ancients, obtain- 
ed chiefly from Asia and Africa. It occurs in yellowish, somewhat 
translucent tears, with a balsam-like resinous smell, and an acrid 
aromatic taste. Sometimes called Gum Thus. It is largely used 
in the manufacture of porous plasters. 

Gum Thus. — A name for gum turpentine, and rarely for 
olibanum. Used with rubber and Japan for waterproofing lea- 
ther. 

Gum Turpentine. — Turpentine hardened by exposure to 
the air. (See Turpentine.) 

Helenite. — Another name for fossil rubber or Elaterite 
(which see.) 

Isinglass. — A substance prepared from the swimming blad- 
ders of certain fish. It is white and glistening, occurring in fibers 
or threads. The best is known as Russian, and comes from Astra- 
chan. Its specific gravity is 1.2. On boiling isinglass it is con- 
verted into a very pure form of glue. Isinglass is used in quick 
drying cements with India-rubber, chloroform being the solvent. 

Idrialin (Idrialit). — A rare hydrocarbon found in Idria, a 
province of Austra, where it occurs with hepatic cinnabar. A 
similar body is obtained in the distillation of amber. Its specific 
gravity is 1.4 to 1.6. Mentioned in certain rubber formulas to 
assist the insulating qualities of compounds. 



126 GUMS AND BALSAMS. 

Kauri Gum. — An amber-like substance varying from a soft 
cream white to an amber color. It comes from New Zealand, and 
is also known as Australian dammar. The lighter colored Kauri 
comes from living trees, but much of the darker is a fossil resin. 
It is cheaper than copal and largely used in varnishes. Kauri 
Gum, in connection with rubber gum and pitch, is used for treat- 
ing yarns used in insulated wire coverings. Parkes added it to 
rubber goods where the surface was to be printed upon after cur- 
ing. One pound of Kauri, 8 pounds of Gutta-percha, and i pound 
of milk of sulphur formed Richard^s covering for insulated wire. 

Lac. — See Shellac. 

Litho-Carbon. — A kind of asphalt large deposits of which 
are found in the state of Texas. It was at one time thought that 
it would supersede India-rubber, and a company was formed with 
the idea of manufacturing goods from it. This was in 1892, and 
India-rubber is still used. The chemical composition of Litho- 
Carbon is 88.23 carbon, 11.59 hydrogen, .06 oxygen, a trace of 
sulphur. Litho-Carbon is jet black in color, is flexible at ordinary 
temperatures, and is quite tough. Its specific gravity is about 
1.028. It is said to be soluble in naphtha, benzol, bisulphide of 
carbon, etc. It will stand a temperature of 600° F., without giv- 
ing off its associate products. It resists alkalies and acids, with 
the exception of concentrated nitric and sulphuric acids. Its man- 
ufacture was patented. Used with Gutta-percha and shellac it 
makes an excellent insulator. 

Manila Gum. — See Gum Elemi. 

Mastic. — A resin from the shores of the Mediterranean. It 
occurs in tears of a pale yellow, is brittle, and of a faint balsamic 
odor. It dissolves in acetone, turpentine oil, and alcohol, and is 
largely used in varnish. The residue obtained in the purifying 
of mineral asphalt is also called mastic. It is used in general rub- 
ber cements for joining stoneware, earthenware, leather, etc. One 
of special value calls for 10 parts of mastic to i part of India- 
rubber, dissolved in chloroform, and makes an excellent cement 
for fastening letters to glass. The gum also appears in many old 
fashioned compounds. 

Menthol is obtained from the oil of peppermint coming from 
Japan and China, or from the oil of spearmint manufactured in 



MENTHOL— OLEO RESINS. 127 

the United States. Its melting point is about 108° to 1 10° F., and 
it is slightly soluble in water, but freely in alcohol. It is often 
used in medicinal plasters which have rubber for a base. 

Mineral India-rubber Asphalt is the name of a material 
composed of refuse tar produced during the refining process of 
tar by sulphuric acid. It is black, like ordinary asphalt, and quite 
elastic. It is an excellent non-conductor of electricity, and is not 
assailed by acids or alkalies. In a naphtha solution, it yields a 
waterproof varnish for metallic objects, and is used in rubber com- 
pounding in place of asphalt. 

Mineral Tallow, also called Hatchetine, is a substance 
found in Siberia, Germany, and Great Britain. It is an earth wax 
that is soft, flexible, and runs from yellow to yellowish white. 
It has no smell, and melts at from 115° to 170° F. It is com- 
posed of 14 hydrogen and 86 carbon. Mineral Tallow is used 
sometimes in place of earth waxes in insulated wire work, and has 
been used in paste blackings in connection with India-rubber. 

Mineral Wax. — A term applied to several waxy-looking 
hydrocarbons found as mineral deposits, such as neft gil (naph- 
tadil), ozocerite, and earth wax. It is found in Austria, and in 
the southern part of Russia, on the shores of the Caspian sea. In 
the United States it occurs largely in Texas and Utah. Used 
chiefly in insulating compounds, (See Ozocerite.) 

Myrrh exudes from the bark of a tree which grows in Ara- 
bia, in yellow drops that are quite oily at first, but which thicken 
and become hard and of a dark color. It appears in commerce in 
either grains, or tears, or in pieces of various sizes and irregular 
form, the color being red, reddish brown, or yellow. Its taste 
is bitter and aromatic, and its smell balsamic. The best gum is 
known as Turkey Myrrh. It is used with rubber, sulphur, and 
salycilic acid in complexion masks. 

Natural Pitch is the name given to such kinds of pitch as 
are not manufactured, such as asphalt, bitumen, etc. — ^that is, 
pitch of a mineral origin, except that from coal or shale. (See 
Asphalt.) 

Oleo Resins. — A resin that contains a certain amount of the 
essential oil of the plant from which it exudes is so called. Chief 
among the Oleo Resins are certain which have a pungent taste 
and a peculiar, and often a pleasant odor, known as balsams. 



128 GUMS AND BALSAMS. 

Ozocerite. — A waxy hydrocarbon occurring in Austria, 
southern Russia, and the United States. It is also known as earth 
wax. Its specific gravity is 0.9 to 0.95, and it is about as hard as 
talc. Chemically, it consists of hydrogen 13.75 ^^^ carbon 86.25, 
while its melting point extends from 140° F. to 170° F. It is often 
found adulterated with asphalt and sometimes with Burgundy 
pitch. Purified Ozocerite is known as ceresine. To make this, 
the crude material is treated with fuming sulphuric acid, and then 
filtered through charcoal. Thus prepared it is of a pale yellow 
color, the melting point ranging from 61° to 78° C. It has almost 
wholly driven out Stockholm tar as a protection for wires insu- 
lated with Gutta-percha, when placed under ground. It improves 
the insulation, but in spite of common belief to the contrary, does 
not preserve textile fabrics. The best compound for the protec- 
tion of the insulation on wire consists of 3 parts of Ozocerite to 
I part of Stockholm tar. It is an insulator of high quality, and 
while it is in some ways intractable, its wax-like nature allows it 
to combine with other insulators or with textiles. It is also used 
as a water-repellent in fabrics, the gum being volatilized by heat, 
and the fumes passed through the cloth. As a surface covering 
for tapes or braid, it is often employed and is better than other 
gums, as it takes a fine polish from the polishing machine. The 
basis of Henley's system of curing India-rubber core is melted 
Ozocerite, which is used under pressure to remove all the mois- 
ture, being afterward heated in hot Ozocerite, which stops up the 
pores. Ozocerite, mixed with India-rubber, is also the basis of 
the India-rubber compound called nigrite. It mixes, however, 
with difficulty with India-rubber, which is an objection to many 
proposed uses of it. It also has a mildly deterious effect on it. 

OzocERiNE is a vaseline-like substance prepared from ozocer- 
ite. There is also prepared from crude ozocerite a valuable black 
wax which, when fused with India-rubber, makes an excellent 
electric insulating material. This wax was recognized by a lec- 
turer before the Society of Chemical Industry as the basis of the 
insulation known as Okonite. 

Paraffine. — A white waxy-looking body obtained from 
certain tars by distillation. It is tasteless, inodorous, harder than 
tallow, but softer than wax. Its specific gravity is .877. It is 



PARAFFINE— PITCH. 129 

also obtained from ozocerite or earth wax. Its melting point 
varies with the source it is obtained from. It is insoluble in water 
and nearly so in boiling alcohol, but soluble in ether, oil of tur- 
pentine, oil of olives, benzol, and bisulphide of carbon. It is usu- 
ally very free from water, and not liable to absorb it. It has been 
used as a waterproofing mixture and is a good insulator. A very 
widely diffused bit of newspaper advice has been that to preserve 
rubber goods they should be dipped in a bath of melted paraffine 
and dried then in a hot room. It has not been proved to be of any 
advantage, however. Experts in the rubber trade claim that such 
a course would seriously injure the elasticity and life of the rub- 
ber. When gossamer clothing was manufactured in large quan- 
tities, the surface of the goods before solarization was covered 
with a thin coat of paraffine, which gave it a peculiar shade until 
the solarization was completed, when all traces of the paraffine 
seemed to disappear. The insulating capacity of rubber to which 
paraffine has been added is quite remarkable, but at the same time 
it lessens the hardness of the rubber to a marked degree. Rubber 
dissolved in Paraffine wax forms a curious compound which has 
been used in insulation. Paraffine is used in the artificial gums 
like Parkesine and insulite ; also with cottonseed oil and resin for 
cheap Brattice cloth, and in cheap proofing compounds. It is not 
a great favorite as an insulator, as it shrinks in cooling, causing 
cracks. Paraffine tapes are also easily destroyed through the 
presence of free acid. It was formerly used largely in covering 
anunciator wires, but as it was found to absorb and retain water, 
its use was given up, and its place taken by a compound of Par- 
affine, ceresin, and resin. 

Pitch is the black residue that remains after the distilling 
of wood tar. Varieties are also obtained from coal tar 
and from bone tar. Wood pitch, however, has a toughness 
which the others do not possess. Pitch was used very early in 
considerable quantities in hard-rubber compounds. Goodyear, for 
example, used considerable of it in hard compounds for coating 
metal, the rest of the compound consisting chiefly of rubber and 
sulphur. It is almost the only organic substance which largely 
increases the resiliency of India-rubber. It is largely used in 
cements, and also in many rubber compounds. Equal parts of 



I30 GUMS AND BALSAMS. 

pitch and Gutta-percha make a tire cement for fastening to the 
rims, known as "Davy's Universal Cement." It is used with 
Gutta-percha in shoemakers' wax, and also in certain proofing 
compounds. Wood cements made of Gutta-percha as a rule con- 
tain a certain amount of Pitch. It is also used in the manufacture 
of Fenton's artificial rubber. 

Resins. — The term given to a number of complex bodies, 
generally the hardened exudation of sap from trees. Chemically 
a resin is the substance obtained by the gradual oxidation of an 
essential oil. The specific gravity ranges between 1.02 and 1.2. 
Resins are divided as a rule into three classes — hard, soft, and 
gum resins. The former at ordinary temperatures are solid and 
quite brittle. They contain little or no essential oil, and are easily 
pulverized. Shellac and sandarac are good examples of this kind, 
and soft resins are usually called balsams, and are either semi- 
fluid, or soft enough to be molded by hand. They are really mix- 
tures of hard resins, and the essential oils found in the plant from 
which they come. On exposure to the air they become in time 
hard resins. Of this class are balsam of storax, tolu balsam, etc. 
Gum resins are the solidified milky juices of certain plants. They 
consist of a mixture of resins, essential oils, and a considerable 
proportion of gum. These are, for example, gum euphorbium, 
galbanum, and to this class also belong India-rubber and Gutta- 
percha. Most of the fossil gums, such as copal, are resins whose 
physical characteristics have been changed by their having been 
buried for a long time in the earth. These fossil resins are coun- 
terfeited to an extent by treating ordinary resin with lime which 
raises its melting point considerably. 

Retinite. — Also known as Retin Asphalt. It is a fossil resin 
found in brown coal. It is found in roundish masses of a yellow 
brown or reddish color, is quite inflammable and readily dissolves 
in alcohol. At present it is somewhat rare, but if it ever should 
become common, it would undoubtedly find a place in rubber 
compounding. Its specific gravity is 1.07 to 1.35. 

Rosin is made from common turpentine, which is distilled 
in water yielding nearly one-fourth its weight of essential oil, 
the residue in the retort consisting of common rosin. Rosin was 
also very generally called colophony, a name now practically obso- 



ROSIN— SHELLAC. 131 

leie. There are two varieties of rosin in common use, the brown 
and the white. The first named is brittle, solid, and of an ambe/^ 
color, and comes from the Norway spruce fir. The white rosin is 
obtained from the pine and is known as galipot. Rosin dissolves 
very freely in alkaline solutions, which allows of its use in soaps. 
Its specific gravity is i .08. There are three grades commonly on 
the market, which are called virgin, yellow dip, and hard. It is 
used in a great variety of rubber compounds, its chief uses being 
in frictions, dry heat varnishes, cements, and puncture fluids. 
Almost all lines of rubber manufacture use a certain amount of it 
at times. Only a small proportion of it can be used in rubber 
compounding, its office being usually that of the sticker. A large 
amount of it induces surface cracking, and often a decided bloom- 
ing of the sulphur. It is also used in waterproof solutions in con- 
junction with spermaceti. India-rubber, and paraffine wax. Mixed 
with boiling oil, it has been applied to Gutta-percha articles to give 
them a Japan-like luster, and is also important in Gutta-percha 
glue, which is compounded of Gutta-percha, powdered glass, lith- 
arge, and Rosin. A very large use for it is in the rubber channel 
cements that are sold to leather shoe manufacturers. 

Sandarac. — Also known as Gum Juniper (which see.) 

Seedlac. — See Shellac. 

Shellac, Sticklac, Seedlac, Gumlac. — All these are dif- 
ferent names for the same thing or different stages of its prepara- 
tion. It is the exudation formed on several sorts of trees growing 
in the East Indies, but is chiefly produced from the banyan tree, 
the exudation coming from a scale shaped insect known as the 
Coccus lacca, the female fixing herself to the bark and exuding 
the resinous substance from her body. In addition to the East 
Indian product there is what is known as Mexican lac, which ex- 
udes from the Croton draco. Sticklac is the resin as taken from the 
tree. Sedlac consists of fragments broken from the twigs and partly 
exhausted by water. Shellac is prepared by melting Stick or Seed- 
lac, straining, and pouring upon a flat surface to harden. It is 
then washed, dried, melted, roughly refined, and sent to market, 
or it is poured into molds to harden and is known as Button or 
Garnet lac. The specific gravity of Lac is about 1.139. It is par- 
tially soluble in alcohol, turpentine, chloroform, and ether, and 



132 GUMS AND RESINS. 

is completely soluble in caustic alkalies and borax solutions. Shel- 
lac was formerly used very generally in rubber manufacture in 
surface goods, and particularly in solarized goods in small pro- 
portions. It has a specific use to-day in the production of water 
varnishes for surface goods. It is also a constituent in the pro- 
duction of certain compounds in hard rubber, and particularly 
the semi-hard varieties, being used to the extent of 20 per cent, 
of the amount of gum. Although quite brittle, it seems to impart 
a certain elasticity to the product. The maximum use of Shellac 
in a hard-rubber compound, according to Hoffer, is 88 parts of 
India-rubber, 50 parts of Shellac, 12 parts of sulphur. It is also 
used in certain of the Jenkins patented packings to the extent of 
10 to 25 per cent, of the amount of rubber, where it is said to 
preserve the compound from the effects of coal oil, steam, or hot 
water. It is also used in many cements both with and without 
India-rubber, one formula for marine glue being : 20 parts of shel- 
lac, 12 parts of benzol, and i part of India-rubber mixed with 
heat. Dissolved in 10 parts of strong aqua-ammonia, it forms a 
varnish for rubber goods, and is also used as a solution for re- 
varnishing old rubber shoes. Used with carburet of iron and 
bisulphide of mercury as a cement for card clothing, with rubber 
and Gutta-percha for attaching shoes to horses, in English "ale 
cement," and in certain proofing compounds. 

Size. — A weak solution of glue, sometimes used in shower- 
proof compounds and cements. The name Size is also often ap- 
plied to any thin viscous substance, as for instance, gilders' var- 
nish. In rubber practice, however, the glue Size is what is 
ordinarily employed. It is also used in preparing a perfectly 
smooth cloth upon which rubber is to be calendered, and from 
which it is stripped before the making up. (See Glue and Gela- 
tine.) 

Spruce Gum is used with chicle in the production of chew- 
ing gums. Melted spruce gum or rosin is known as Burgundy 
pitch (which see.) 

Stearine. — A white waxy-looking body obtained from fats. 
— chiefly tallow and palm oil. When made from tallow it is 
called pressed tallow or tallow Stearine, which is the solid part 
obtained from the heating of suet fat and the removal of the 



STEARIN E PITCH— TAR 133 

liquid part which is oleomargarine. Tallow Stearine is very 
largely used in candle making, where is found saponified Stearine. 
distilled Stearine, and distilled grease Stearine. This latter con- 
tains considerable cholestrol and differs from commercial stearic 
acid or Stearine chiefly in its physical structure. Stearine is used 
in prootfing compounds, in rubber blackings and in compounds 
containing resins. It has been suggested that a small proportion 
of Stearine in certain rubber compounds that contain low grades 
of rubber which in themselves have large proportions of resin, 
has a decided value in preventing oxidization. Used in proofing 
compounds, rubber blackings, and compounds containing resins. 

Stearine Pitch. — The brown tarry residue left in the still 
during the process of refining tallow and fat. Used in the manu- 
facture of certain packings that contain no rubber. Stearine 
Pitch is also used as a lubricant for bearings that have a ten- 
d ency t o heat. 

Stick Lac. — See Shellac. 

Stockholm Tar is used in black cements of the marine glue 
class, and is also used in rubber compounding, its office being to 
assist in the mixing of dry compounds, and as a binding material 
for sulphur in the dry heat cure. Also used in manganese cements 
and in cements to fasten tiles to floors. (See Tar.) 

Spermaceti. — A peculiar fatty concrete substance obtained 
from the head of the sperm whale. Its specific gravity is 0.943, 
and it is fusible at 112° F. Insoluble in water, soluble in hot 
alcohol, ether, and oil of turpentine, but redeposited as the liquids 
cool. Was formerly used in certain waterproofing compositions. 

Sludge Oil Resin. — A heavy gummy residue from the waste 
of superphosphate factories. Has been used with rubber in mak- 
ing Japan varnishes. 

Tar. — This substance is derived from the animal, vegetable, 
and mineral kingdoms. From the first, by the destructive distillation 
of bones, is produced what is known as "DippeFs oiP ; from the 
second, by the distillation of pine woods, the product is known 
as pine tar or Stockholm tar ; and from the third, by the distilla- 
tion of coal, is produced coal tar. Of the three, coal tar is the 
most used in rubber work, its office being to help carry adulterants 
in dry mixing and to keep the sulphur from blooming after vul- 



134 GUMS AND BALSAMS. 

canization. It is used chiefly in dry heat work. Goodyear dis- 
covered early that very large quantities of boiled tar could be used 
in connection with India-rubber and sulphur without injuring the 
quality of the gum, and it has been very generally used since his 
time. 

Trinidad Asphalt is obtained from the pitch lakes of the 
island of Trinidad. Its specific gravity is 1.2, and it is somewhat 
soluble in alcohol, while Persian naphtha, oil of turpentine, benzol, 
and benzoline readily dissolve it. (See Asphalt.) 

ToLU Balsam is derived from a tree found on the mountains 
of Tolu, and the banks of the Magdalena river, in Colombia. It 
is very similar to balsam of Peru. It sometimes appears in com- 
merce in dry friable fragments, the newly imported gum being 
soft and tenacious. It has a very fragrant odor, and a medicinal 
and tonic effect. Tolu Balsam is used with paraffine wax and 
chicle in chewing gum compounds. 

Turpentine. — This is a semi-solid resin, which comes from 
various species of pine as a rule. The chief commercial varieties 
are common turpentine, which comes from the Pinus ables; Venice 
turpentine, from the larch ; Bordeaux turpentine, from the Pinus 
maritima, and Chian turpentine, from the Pistacia lentiscus. Of 
these the Venice turpentine is said to be the best. It is of a pale 
yellow color, transparent, has a bitter taste, but a balsamic odor. 
Used instead of rosin in many compounds. 

Vegetable Pitch. — The residue left after distilling the tar 
made from wood of various trees. Called vegetable to distin- 
guish it from the mineral pitch which is derived from coal. (See 
Pitch.) 

Xanthorrhoea Gum is somewhat similar to shellac, is 
abundantly produced in the Australian colonies, and sometimes 
used in the compounding of ebonite. Xanthorrhoea Gum is also 
sometimes known as gum acaroides, and is produced from the 
Australian grass tree. 

Xyloidin. — An artificial gum much resembling pyroxylin 
obtained by the action of nitric acid on starch. 

Xylonite. — See Zvlonite. 



CHAPTER VIII. 

PIGMENTS AND PROCESSES USED IN COLORING INDIA-RUBBER. 

Most of the India-rubber goods manufactured to-day are 
black, this color, if it may be so called, being produced in a mea- 
sure by the color of the rubber, together with the leads and other 
ingredients, most of which darken during vulcanization. The 
next prominent color, from a rubber standpoint, is white, pro- 
duced by either an oxide or sulphide of zinc. Next to this range 
the yellows and reds, produced by sulphide of antimony and ver- 
milion. 

So many colors are unstable when brought in contact with 
sulphur during the heat of vulcanization, and it is so difficult to 
get good effects, that it is not to be expected that beautiful colors 
in India-rubber will ever become common. There are various 
methods used for changing the natural color of India-rubber. The 
usual way is by incorporating, by mechanical mixture, earthy pig- 
ments or metallic oxides or sulphides, or vegetable coloring mat- 
ters, which, by their covering property and strength, give to the 
India-rubber their own particular shade. There are other me- 
thods, however. For example, there have been produced anilines 
soluble in benzine, that are used for surface work, such coloring 
being really an elastic enamel. Toys and minor articles that are 
ornamented in very bright colors, however, are generally painted 
over after vulcanization, but paint is not durable, nor does it long 
remain beautiful. 

While it is claimed ordinarily that it is impossible to dye 
India-rubber, it should be remembered that the attractive colors 
that appear on childrens' toy balloons and similar pure gum goods 
are applied as dyes, the colors being analines, with methylic alco- 
hol as a base. These colors are boiled in rainwater, and when the 
solution is cold the balloons are put into the coloring liquid and 
turned so as to have their entire surface wetted. After that, they 
are dropped into cold water, which washes off the superfluous 
color. When this is done properly, the rubber does not give off 
any stain at all after the first washing. The colors used in this 
way are red, green, blue, orange, and pink, but other shades are 
equally available. 

135 



136 COLORING MATTERS AND PROCESSES. 

In Germany a full line of aniline colors soluble in benzine 
is now manufactured, and for surface coloring of rubber goods 
they have been found very valuable. Although they are not abso- 
lutely fast, they are sufficiently so for all practical purposes. In 
many cases, these aniline colors, being soluble in benzine, can be 
mixed right with the India-rubber — that is, when it is used in the 
form of solution. If the product is cured in open steam heat with 
sulphur, some very curious effects are likely to be obtained. This 
was proved some years ago when a line of rubber colors was put 
on the market in the United States, with white oxide of antimony 
as a base, and anilines to give various shades. It does not often 
happen, however, that a problem of this kind confronts the users 
of aniline colors in rubber, the more general and sensible way being 
that of surface coloring. This is done in some cases by simply 
brushing the aniline color dissolved in benzine over the surface of 
the article. It is desirable, however, first to dip the goods in the 
dissolved mordant, and then to use the brush, if necessary. Where 
a high polish, or a polished effect is desired, some sort of elastic 
lacquer must be put on over the coloring matter. A very thin 
India-rubber solution is often used for this. 

In speaking of anilines, it must be remembered that those 
that have to be worked up with acids should be avoided for rub- 
ber work, but there are so many others that there is no need of 
the rubberman making this mistake. Where colors are to be 
printed upon rubber surfaces, a little dextrine is added to the ani- 
line dissolved in benzine, and to make the color dry faster, a little 
sulphate of manganese mixed with half of i per cent, of alum and 
added to the mass is advisable. 

Black, blue, red, yellow, and green anilines are also used in 
coloring rubber cements that go to the leather shoe trade. These 
and other anilines are also used very generally in artificial leather 
compounds. Aniline, black, is used in water varnishes for luster 
coats and blankets. 

It is also a good idea to sponge the rubber surface with a 
water solution of alum before the color is applied. The use of 
alum as a mordant may be supplanted by bisulphate of soda, if it 
is desired. The best colors available in the aniline series are reds, 
particularly magenta reds, and the marine and alkali blues. 



WHITES. 137 

A great many methods of surface coloring have been devised, 
some of them being ludicrous attempts at dyeing rubber. The sur- 
face of rubber is, of course, not easily affected by colors, unless it 
has first been attacked and roughened by some powerful solvent. 
Malcolm's process for this surface coloring is perhaps as harm- 
less as any. This method is to expose the rubber to the sunlight 
while it is immersed in alcohol. When the surface is somewhat 
disintegrated, the rubber is taken out, washed, and dipped in a 
dye solution. 

The colors that follow are described very briefly, and most 
of them are such that any rubber manufacturer can easily secure 
them for use or for experiment. 

WHITE. 

Only a few colors are available for use in making white 
rubber goods. Of these, the zincs take the lead, being by far the 
most constant and valuable. They lend their color to the mass 
simply by their presence as dry paints with strong coloring quali- 
ties. 

Oxide of Zinc is used more than any other coloring matter 
in the production of white rubber. It is especially valuable be- 
cause during the process of vulcanization it increases the white- 
ness of the goods. This is because the part of the zinc oxide that 
is turned into the zinc sulphide is a stronger white than the first- 
Oxide of zinc made of pure spelter is the best. Where lead and 
zinc ores are found together it sometimes happens that the oxide 
contains a certain amount of lead, and then its value as a coloring 
matter is injured. It is prepared by two processes, an air blast, 
and a steam current ; in other words, by a dry and a wet process. 
That prepared by the wet process, even when strongly heated, con- 
tains more water than does that produced by the dry process. The 
specific gravity of zinc oxide is 5.61. A certain percentage of this 
oxide is often added to dark colored goods to increase the resili- 
ency of the rubber. It also increases the hardness of a compound 
where soft gums are used. Manufacturers of insulated wire find 
that it increases the insulating qualities of rubber when added in 
moderate quantity. 

Zinc White. — See Oxide of Zinc. 



138 COLORING MATTERS AND PROCESSES. 

Sulphide of Zinc. — This is a white that is fully equal to the 
popular oxide, and does not alter its tint under the influence of sul- 
phur and heat. It is said to exert a distinctly preservative action 
upon India-rubber. Sulphide of zinc, pure and in combination 
with other materials, and under various names, has been sold very 
largely to rubber manufacturers. It is deemed especially valuable 
in white goods cured with dry heat. It is used in high grade 
white stocks, and even in pink dental rubber. It also assists in 
the vulcanization of rubber. 

Oleum White. — A high grade of sulphide of zinc, in which 
is a certain proportion of blanc fixe. It is a trifle heavier than a 
pure sulphide of zinc, but in practice has been found to be equal 
if not better than either the sulphide or oxide of zinc in the manu- 
facture of certain white rubbers. 

Carbonate of Zinc. — This is a form of zinc rarely known to- 
day in rubber mills. The first white rubber, however, was made 
of it under a patent granted to that eminent rubber manufacturer, 
the late Henry G. Tyer. It is a white powder, and is a mixture of 
equal quantities of sulphide of zinc and carbonate of sodium, 
and subsequently the boiling of the same for a short time. 

Borate of Zinc. — A zinc salt, precipitated by 20 to 30 per 
cent, of a soluble borate, the result being a white powder, which is 
claimed to have a distinctively preservative influence when used 
in rubber, while the tensile strength of the gum is much enhanced. 

[Lascelles-Scott.] 

Calamine White. — This is prepared from the native carbon- 
ate of zinc, by calcining and grinding. It is not a strong white, 
and is not nearly as good as the oxide or carbonate of zinc as a 
coloring matter. For a cheap white, and a filler, however, it is 
useful. Although the German anti-poison act of 1887 prohibits the 
use of zinc as a coloring matter, it does not apply to its ordinary 
use in rubber compounding. They rule that zinc compounds not 
soluble in water may be used in rubber when and where the color- 
ing matter is mixed in the mass before vulcanizing, or as a color 
layer on the surface if it is covered with a lacquer varnish. 

Barium White. — This is also called constant white, and 
comes from the sulphate of barium or heavy spar. In treatment, 
it is ground very fine, treated with hot hydrochloric acid, washed, 



BLACKS. 139 

dried, sifted, and then forms a fairly white, dense, impalpable 
powder. The pure article, obtained by precipitation, is a brilliant 
white, and is often used in rubber compounding. It is one of the 
few metallic colors that the German anti-poison act allows manu- 
facturers to use in any way they please. 

Griffiths^s White is a sulphide of zinc of English manu- 
facture, prepared by precipitation, and containing a certain pro- 
portion of magnesia. 

Fard^s Spanish White. — Also known as Pearl White. A 
tri-nitrate of bismuth, and a white that, it is said, has a future in 
rubber compounding. It is not easily affected by atmospheric in- 
fluences, or by the action of sulphurous compounds. 

[A. Camille.] 

Lithophone. — A sulphide of zinc in which is found a certain 
percentage of barium. It is a constant white, and is largely used 
instead of oxide of zinc for white goods, particularly in the manu- 
facture of druggists' and surgical sundries. 

BLACK. 

There are more methods of getting black rubbers, than 
allmost any other color, as the tendency of the gum itself is to 
darken under heat and the action of sulphur, and the sulphides of 
most materials that are used in the compounding have the same 
effect. Most rubber goods are made up without regard to 
color, and are usually a dirty brownish-black, tempered by the yel- 
low of the sulphur bloom. Where a genuine black is wanted, 
however, some of the vegetable blacks or perhaps certain of the 
leads are employed. Lampblack is one of the most common in- 
gredients used. 

Lampblack. — Pure Lampblack is pure carbon, as indeed is 
the diamond. Lampblack, however, is carbon in its amorphous 
or spongy form, while the diamond is crystaline. It is obtained on 
a large scale by collecting the smoke produced during the com- 
bustion of oils, fats, resins, coal, gas, tar, wood tar, petroleum 
residues, dead oil, and even bituminous coal. This accounts for 
the various grades that are to be found on the market. Large 
quantities of Lampblack have also been manufactured from natural 
gas. There are many types of Lampblack, the best in the world 



140 COLORING MATTERS AND PROCESSES. 

being employed in the preparation of Indian ink. This is made 
from burning camphor, a lower grade being made from the mix- 
ture of camphor and other oils. The smoke is collected on leaves, 
washed, dried, and sifted with the utmost care. The lines of rub- 
ber goods in which it is generally found are rubber boots and 
shoes, surface clothing, and carriage cloth, druggists' sundries 
(where the leads are deemed dangerous), and in certain composi- 
tions where emery is the chief ingredient used for grinding or 
polishing. A curious fact about Lampblack is that a little bit of 
it in unvulcanized, erasive rubber, seems to assist the erasive 
quality, and does not cause smutting. A little of it is also some- 
times added to churning mixtures that do not readily mix. The 
following analysis of the composition of lampblack is given by 
Braconnot : 

Carbon 79. i 

Water 8.0 

Resinous matter 5.3 

Bituminous matter or pitch 1.7 

Sulphate of ammonium 3.3 

Sulphate of calcium .8 

Sulphate of potassium .4 

Chloride of potassium traces. 

Phosphates of calcium and iron .3 

Siliceous or earthy matter i .1 

Total loo.o 

The analysis of lampblack from a large black manufactory 
in the United States : 

Carbon 79. i 

Empyreumatic resin \ soluble m alcohol.. 5.3 

^^ I insoluble in alcohol 1.7 

Humin 0.5 

Sulphate of ammoii'uTr: 3.3 

Sulphate of lime . . 0.8 

Sulphate of potash 0.4 

Phosphate of lime 0.3 

Water 8.0 

Chloride of potassium trace only. 

Sand (accidental) <S.6 

Total loo.o 

BoNEBLACK, also Called animal charcoal and sometimes ivory 
black, is a black powder obtained by grinding the product of bones 
that are burned at a red heat in close vessels. It resembles vege- 
table charcoal, but is more dense and less combustible. A good 



BLACKS. 141 

quality should have an even color, of a rather dull shade. On 
analysis, boneblack shows the following: 

Phosphate of lime, 78.0 

Phosphate of magnesia 1.5 

Carbonate of lime 8.5 

Carbon lo.o 

Impurities, silica, iron, etc 2.0 

Total 100.0 

Sulphide of Lead. — This is a valuable coloring matter for 
rubber, as it gives a good black, besides which it makes goods ex- 
ceedingly resilient. There are great differences in the production 
of lead sulphides, but, as before remarked, a good one is of special 
value to rubber manufacturers. (See Leads.) 

Mineral Black is a pigment that is said to be made from 
bituminous lignite. It is very porous, and is not recommended 
for rubber work. A very little ultramarine blue added to a black 
in rubber, sometimes overcomes the grayish shade. 

Sulphide of Uranium. — A fine black pigment more intense 
than plumbic blacks. It is a permanent color, and is said to be a 
preservative of rubber. 

Black Hypo. — This is also known as hyposulphite of lead. 
It is really a mixture of thiosulphate of sodium mixed with ace- 
tate of lead, and appears as a fine white crystaline precipitate, 
which should be called thiosulphate of lead. There are two forms, 
the white hypo and the Black Hypo, the difference being that the 
white when heated is transformed into a soft black powder con- 
taining very little free sulphur. The black of the compound being 
sulphide of lead often contains over 90 per cent, of pure sulphide. 
It is an excellent vulcanizing agent, and also a filler. When pro- 
perly prepared it makes goods absolutely free from bloom. 

Carbon Blacks of late have been used very largely in rubber 
compounding and have done excellent work. They are not as 
black, as a rule, as the better grades of lampblack made 
from oils or resin. They are in many cases wholly inert, how- 
ever, and therefore perfectly safe to use. One of the best types 
of this sort of coloring matter comes from a graphite mine in the 
United States. It is wholly amorphous, and has none of the flaky 
make-up that ordinary graphite has, and is 97 per cent, pure car- 
bon. Carbon Blacks, it is also said, give a brighter finish to var- 
nished goods than ordinary lampblacks. 



142 COLORING MATTERS AND PROCESSES. 

Oak Black. — A product of the distillation of oak wood after 
draining off (i) wood alcohol and (2) a product resembling tar. 
It is used in certain black insulating compounds in connection with 
shellac, coal tar, paraffine, and asbestos. 

BLUE. 

Blues are not largely used in general rubber work. They 
are found chiefly in toys, in sheetings, and in certain packings. 
The most important blue is — 

Ultramarine. — This is made from lapis lazuli. The exact 
composition of this coloring matter is not known, but it is said to 
be based on a silicate of alumina with sulphide of sodium. An 
artificial ultramarine is often produced which is equal and often 
superior to the natural pigment. This is made of kaolin, carbon- 
ate of sodium, willow charcoal, and sulphur. The following 
analysis of natural Ultramarine is given : 

Silica 37-6 

Alumina 27.4 

Sulphur 14-2 

Soda : 20.0 

Analyses of the best artificial Ultramarines show these figures : 

Silica , 40.25 39.39 40.19 

Alumina 26.62 24.40 25.85 

Sulphur 13.42 12.69 13-27 

Soda 19.89 21.52 20.69 

Ultramarine appears in commerce as a fine blue powder of 
various standards of fineness. Acids readily destroy it, but alka- 
lies have no effect on it. It stands heat well, not changing below 
a low red. It is used in cements for backs of memorandum blocks, 
and in blue soft rubber goods, particularly in vapor cured goods, 
such as sheeting. When mixed with chrome yellow it makes a 
green; with colcothar, it makes a violet. Mixed with rose pink, 
oxide of zinc, and Indian red, it produced the well-known wine- 
colored coat that was so popular a few A^ears ago. It is claimed 
that Ultramarine blue keeps rubber from overcuring, and that it 
is, therefore, a most useful ingredient to add to compounds that 
are exposed to heat. 

Yale Blue. — In certain soft rubber goods, where a strong 
blue is needed, ultramarine was found unsatisfactory. A firm of 
rubber chemists therefore produced Yale Blue, which is a strong 



BLUES. 



143 



coloring matter, and wholly inert as far as the rubber is concerned. 
Smalts. — This is what may be called a deep tinted cobalt 
glass. The analysis of Smalts of good quality is as follows : 

Deep-colored Pale-colored 
Norwegian. German. 

Silica 70.9 72. 1 

Potassa (with traces of soda and lime) 20.4 20.0 

Oxide of cobalt 6.5 2.0 

Alumina .4 i.8 

Peroxide of iron .3 1.4 

Other earths and oxides, and loss 1.5 2.7 

Total loo.o loo.o 

This is one of the few colors that are practically indestructa- 
ble. In using Smalts for the pigment, large quantities are neces- 
sary, as the color is not exceedingly strong, 

Cobalt Blue is manufactured from oxide of cobalt, phos- 
phate of cobalt, and alumina. It is rarely used in coloring rubber 
where the ingredients are to be mixed with the mass, ultramarine 
being much superior. Also called Smalts. 

Thenards blue is similar to cobalt blue, but is a more beau- 
tiful pigment. It is used chiefly as a surface color. White pig- 
ments in small quantities added to this blue make beautiful tur- 
quois colors. 

Prussian Blue. — A dark brilliant blue compound, having 
iron for a base. There is a soluble and an insoluble variety of 
this compound which is of a somewhat complex chemical con- 
stitution. Heated strongly in the air, the insoluble form of Prus- 
sian Blue burns like tinder. When boiled with caustic potash, it 
is decomposed. If the dry powder be strongly rubbed in a mortar, 
it assumes a copper red luster. In commerce it occurs in irregular 
shaped masses, having a characteristic conchoidal fracture and 
copper red luster. 

Chrome Blue is manufactured from silica, fluor spar, and 
chromate of potash. The resultant material is a deep blue, vi- 
trious mass which is reduced to an impalpable powder. It is less 
sensitive to acids than ultramarine, and is better adapted for rub- 
ber goods. [Jules Garnier.] 

Molybdenum Blue. — A pigment recommended by Lascel- 
les-Scott, which is a natural bisulphide of molybdenum, found 



144 COLORING MATTERS AND PROCESSES. 

chiefly in Sweden. It is an exceedingly beautiful blue, but at 
present is rare. The distinguished chemist above quoted men- 
tions that large new deposits of this mineral have been found in 
the United States and Australia, and that it is likely to be so 
cheapened that it will be a valuable rubber pigment. 

Indigo Blue is prepared from plants of the indigofera genus. 
Pure Indigo is insoluble in water, nor is it soluble in weak acids 
or alkalies. A small percentage is dissolved in alcohol and its 
solution is more considerable in turpentine. Indigo Blue for rub- 
ber is said to be valuable on account of its preserving qualities, 
which are double that of other blues. 

RED AND BROWN. 

The strong red coloring matters used in rubber work are 
mostly of a mercurial base. These are vermilion, red chromate of 
mercury, sulphide of mercury, and iodide of mercury. The 
Chinese vermilion, which is the best, is prepared by a special pro- 
cess of their own, and contains 89 per cent, of pure mercury, the 
rest being sulphur. This coloring matter is used very largely in 
dental vulcanite, small amounts of it also giving excellent shades 
in soft rubber goods. Cinnabar and Paris red are also mercurial 
sulphides, and very strong colors. The sulphides of mercury are 
really the only ones that are safe and valuable for producing these 
colors. Red chalk and natural clay containing a certain amount of 
iron are used chiefly as fillers in rubber goods, although a certain 
quantity of them produce a dark red color. 

Vermilion. — The red form of mercuric sulphide is a scarlet 
red powder of specific gravity 8.124. It is sometimes adulterated 
with red lead or red oxide of iron, but such adulterations can be 
detected by heating a small sample of the suspected article on a 
porcelain or platinum dish. If any adulterant is present it will 
remain behind as a residue, since pure Vermilion is completely 
volatile. This substance is sometimes called cinnabar. A substi- 
tute for vermilion in hard rubber was brought out by John Hali- 
day in 1870. This was a mixture of garancine and cochineal, in 
water solutions, boiled and mixed in the proportion of 5 parts of 
garancine liquor to i part of cochineal liquor. To each gallon 
of this compound liquor 2 potmds of pure oxide of antimony was 



REDS AND BROWNS. 145 

added; then, after heating until the water was evaporated, the 
new coloring matter perfectly dry. Another substitute for ver- 
milion was white oxide of antimony. According to A. D. Schles- 
inger, the veteran of hard rubber experts, white oxide of antimony, 
when mixed with India-rubber and sulphur, will, during vul- 
canization, impart to hard rubber a light red color very similar 
to that obtained by the use of vermilion. The proportion of sul- 
phur is the same as is used ordinarily in making vulcanite, while 
to each pound of rubber is added 12 ounces of antimony sulphide. 

Red Oxide of Iron. — This is familiar as iron rust. It is arti- 
ficially prepared and forms a scarlet powder of a specific gravity 
of 4.46. This contains about 5 per cent, water of crystalization, 
which cannot be driven oil at temperatures up to 212° F., and 
with difficulty at higher ones. (See Colcothar.) 

Peroxide of Iron. — An old name for the sesquioxide of iron, 
now called ferric oxide. (See Oxide of Iron.) 

Princess Metallic Paint. — An oxide of iron. 

Indian Red. — Another name for oxide of iron. 

Red Hematite. — An ore of iron, somewhat soft and friable. 
Specific gravity 5.19 to 5.28. Composition 70 per cent, iron, 30 
per cent, oxygen. Insoluble in water, alcohol, or rubber solvents. 
As a colorant in rubber work it is unchangeable chemically. Used 
in packings and for dark maroons. 

Venetian Red. — See Colcothar. 

Red Ochre. — An impure oxide of iron. A dull red earthy 
substance containing clayey matter, and having a specific gravity 
of about 5.2. Used chiefly as a filler, as the color is not strong. 
As far back as the time of Dr. Mattson, Red Ochre, Venetian red, 
and Indian red, were advised by him for use in rubber com- 
pounding. Indeed, he obtained a patent for packing in which 
Venetian red was the principal adulterant. 

Orange Vermilion gives a very handsome color in connec- 
tion with rubber, but is rarely used, as it is not permanent if other 
metals, such as copper, brass, iron, and zinc, come in contact 
with it. 

Crimson Sulphide of Antimony. — This is altogether the 
best antimony color now in use. It not only gives a fine shade of 
orange or red, but it also is an excellent vulcanizing agent. 



146 COLORING MATTERS AND PROCESSES. 

CoLCOTHAR. — A form of oxide of iron of the specific gravity 
of 4.8 to 5.3. It is the residue left in the manufacture of fuming 
sulphuric acid from green vitriol. The least calcined portions, 
which are scarlet in color, are termed jewelers' rouge, and the 
more calcined parts, of a bluish shade, are called crocus. Its 
composition is that of ferric oxide. In its reaction it is indifferent, 
being very stable under ordinary conditions. Colcothar is a dull 
red and is often used in red packings, soleings, etc. Many rubber 
chemists prepare their own Colcothar, as they are able to get 
brighter shades than is possible from the goods ordinarily sold in 
the open market. 

Umber. — A brown earthy mineral, containing chiefly the 
oxides of iron and manganese. The following analysis, by Prof. 
A. H. Church, is taken from a choice specimen of Cyprus Umber : 
Oxide of iron, 48; oxide of manganese, 19; silica, 13.7; water 
yielded at a heat of 212° F., 4.8; mixture of lime, magnesia, 
alumina with organic matter, 14.5. In using Umber for rubber 
compounding, care should be taken to dry the material thoroughly 
at 212° F., before it is used. Burnt Umber is the product obtained 
by roasting the above material. It is slightly redder in color and 
will naturally contain less water. For brown colors, in addition 
to Umber, various natural earthy matters are used, as are also 
oxy-sulphide of antimony and sepia, the latter being an animal 
coloring matter made from the bright fluid formed in the ink bag 
of cuttle fishes. Sienna and chestnut brown are practically the 
same as Umber, while Vandyke brown is made of oxide of iron, 
ground very fine, and is not injurious to rubber. While these in- 
gredients are practically inert, they do not make the best of rub- 
ber compounds, as the resulting compound is apt to have a hard 
stony feeling. 

YELLOW. 

Yellows are not often demanded in rubber work, except in 
a few fancy articles and in hose markings. The most common 
is that produced by the golden sulphuret of antimony, but color 
is not what is sought in the use of that ingredient, but rather the 
excellent rubber produced by it when used instead of sulphur. 
Other mineral yellows used are strontium, chromium, cadmium. 



YELLOWS. 147 

barium, and arsenic. Chrome yellow is made from a lead base 
which darkens when subjected to vulcanization. 

Cadmium Yellow. — This is the best pigment for producing 
yellow in a rubber compound. It does not injure the elasticity 
or strength of the India-rubber in any way, and, while it has no 
special effect on vulcanization, perhaps hurries it a little. It is 
not injurious to the health of persons using it, and is generally 
used for surface ornamentation of toys, etc. It is sometimes mixed 
with yellow sulphide of tin to cheapen it. While Cadmium was 
ruled against in the German anti-poison act, the sulphides of this 
metal were made an exception, and said to be safe. In dental 
plates, however, where the coloring matter was used in large 
quantity, it was advised against. The costliness of Cadmium 
Yellow at present bars its general use in rubber. 

AuREOLiN Yellow. — A very handsome color, and one that 
is stable and brilliant. It is made up of acetate of cobalt and 
nitrate of potassium. The color stands the light well, and sulphur 
compounds have little influence upon it. This is chiefly used for 
surface work. 

Gamboge Yellow. — Obtained from the Garicinia morella. 
It contains from 20 to 25 per cent, of gum, 65 per cent, of resin, 
3 per cent, of volatile oil. It is soluble particularly in spirits, in 
a number of oily liquids, and partially in water. Finely pulver- 
ized Gamboge may be mixed with rubber, and is said to be a pre- 
servative of it. 

Barberry Yellow. — Made from the root or bark of the 
Barberis vulgaris. It is largely used in coloring leather surfaces, 
and, in connection with gamboge, is said to be useful in rubber 
work. 

Yellow Ochre. — There are several ochres, all of them being 
practically oxides or iron. They are earthy substances of no par- 
ticular reaction, very stable, having a specific gravity about 5. 
Their low cost renders them available for almost any work, but 
the colors produced are not especially beautiful. 

Arsenic Yellow. — Also known as king's yellow, and is a 
term applied to sulphide of arsenic. A cheap grade of this, which 
is really only an imitation, is manufactured by mixing together 
litharge and white arsenic, and grinding the product. Either of 



148 COLORING MATTERS AND PROCESSES. 

these, of course, is poisonous, and they are very rarely used or 
needed in connection with rubber. The specific gravity of Arse- 
nic Yellow is 3.48. Although a sulphide, there is not enough 
sulphur in its composition to vulcanize India-rubber. On account 
of its poisonous properties, this yellow has been largely super- 
seded commercially by the comparatively harmless chrome yel- 
lows. Another name for this color is orpiment. It was often 
used in rubber compounds of twenty years ago. A small quantity 
in white zinc stock takes off the glaring white effect, and pro- 
duces a handsome cream white. Must be in an impalpable powder 
to bring out the color. 

Chrome Yellow. — Ordinarily the chromate of lead, which 
is largely used as a pigment. It is somewhat poisonous and is 
apt to oxydize organic substances, particularly if sulphur is pre- 
sent. Has been used in the surface ornamentation of rubber toys, 
but such use is generally condemned. The only Chrome Yellows 
that are really valuable for rubber work are the chromate of zinc, 
or possibly the chromate of strontium. 

Orpiment. — See Arsenic Yellow. 

GREEN. 

It is fortunate that greens are not largely sought in the rub- 
ber industry, for they are rare. Arsenic greens in many cases are 
not to be thought of ; therefore about the only ones that are avail- 
able, unless very high cost goods can be utilized, are the fol- 
lowing : 

Chrome Green. — A coloring matter that is not affected by 
strong acids, or alkalies, and which is inert when mixed with 
India-rubber. It is the best mineral green that can be used in 
connection with rubber. It is really a sesquioxide of chromium ; 
and may be mixed with rubber, with any kind of solvent, and 
with other oxides and pigments, without hurt to the compounds. 

Terra-verte is of mineral origin, and is imported in large 
quantities from Italy. It is a pale neutral green of moderate cost, 
and is not injurious to rubber. On analysis it shows: 

No. I. No. 2. 

Silica 51.50 46.00 

Alumina 12.00 11.70 

Protoxide of iron 17.00 17.40 

Lime 2.50 3.00 



GREENS. 149 

Magnesia 3.50 8.00 

Soda 4. 50 .... 

Water 9.00 i3-90 

Total 100.00 100.00 

The analysts of the above were, of No. i, Klaproth; of No. 
2, Berthier. 

Green Ultramarine is made by a process very similar to 
that made in producing blue of that name, and its action upon 
rubber is almost identical with that of ultramarine blues. 



CHAPTER IX. 

ACIDS, ALKALIES, AND THEIR DERIVATIVES, USED IN THE RUBBER 
MANUFACTURE. 

As a rule neither acids nor alkalies, in the strict sense of the 
term, are largely used in ordinary rubber compounding. In a 
great many of the processes, however, that go far to make up 
finished goods, acids are used, as, for example, in those employed 
in the reclaiming of rubber chemically. Alkalies also are most 
necessary, a notable example being the use of caustic potash and 
caustic soda solutions in removing sulphur from manufactured 
goods. A great variety of uses other than these are indicated in 
the following pages: 

Acetic Acid. — This is usually obtained by the dry distilla- 
tion of wood fiber, peat, or sawdust. The strongest form is 
known as glacial and occurs in large watery crystals, readily 
liquified. The common commercial acid usually has a brown or 
yellowish color, due to impurity, since the pure acid is colorless. 
Its specific gravity is 1.05, and it has a characteristic odor familiar 
enough in vinegar. As an acid it is not very corrosive, and its 
compounds are easily decomposed by mineral acids. It is quite 
volatile. The primary use of this acid in connection with India- 
rubber is in the coagulation of rubber milk. It is a prominent 
component part of the smoke used in coagulating fine Para rub- 
ber. It has also been used under the Vaughn process for coagulat- 
ing Balata, and in the manufacture of certain substitutes like lin- 
oxin, Parkesine, etc. ; in connection with nitro-cellulose and castor 
oil in the production of certain waterproofing compositions; by 
Brooman in separating whiting, white lead oxides, etc., from vul- 
canized rubber; and in shoemakers^ blackings in connection with 
caoutchouc oil, vinegar, molasses, and lampblack. 

Ale. — A beer made from malt, distinguished chiefly by its 
strength and the quantity of sugar remaining undecomposed, 
which enables the liquor to keep, without requiring a large amount 
of hops. A mixture of ale and linseed oil, in the proportions of 
8 parts ale to 2 parts linseed oil, is used in dissolving isinglass, 
in which is afterward incorporated shellac and India-rubber in 
the formation of what is known as ale cement. 

150 



ALUM— AMMONIA. 151 

Alum. — A general term for several chemical compounds of 
aluminum, potassium, chromium, and ammonium. Common alum 
is the double sulphate of potassium and aluminum, having a spe- 
cific gravity of i .7 and containing 45 per cent, of water of crystali- 
zation, one-quarter of which is expelled on heating to 140° F. It is 
soluble in waterQl^ parts per 100 when cold, 357 parts per 100 when 
hot. Chrome Alum is a double sulphate of chromium and potas- 
sium, its specific gravity being 2.y, and containing 43 per cent, 
water of crystalization, which is almost entirely lost at 392° F. 
It occurs as dull purple crystals, slowly soluble in water to 20 per 
cent, in the cold and 50 per cent, in hot water. Its action on gela- 
tine is remarkable for its hardening qualities. Ammonia Alum, 
the double sulphate of aluminum and ammonia, is largely used 
in place of common alum. It contains 48 per cent, of water of 
crystalization and has a specific gravity of 1.63. Strongly heated, 
it yields sulphate of ammonia water and a very small quantity of 
of sulphuric acid, while alumina is left behind. It is soluble in 
water 13 per cent, cold, 422 per cent. hot. Roman Alum has the 
same general characteristics as common alum, but contains a lit- 
tle more alumina. 

Alum is used in many of the shower-proof mixtures for cloths 
of the cravenette order, that are to-day bought and made up by 
manufacturers of mackintoshes. It is also sometimes used in the 
manufacture of sponge rubber. By Garnier's process it is also 
used in spirituous solution to cure rubber without heat by mixing 
with it. Used also in Wray's substitute for Gutta-percha. 
Alum was used in Payne^s Gutta-percha compounds for proofing, 
varnishing, and paints. Ghislin, who prepared some curious 
compounds from seaweed and India-rubber, mixed alum, gela- 
tine, and metallic oxides in his compounds. It is also sometimes 
used in compounding rubber to make sponge effects and mixed 
with sulphate of iron and soap, in a water mixture with boiled 
linseed oil, to make flexible waterproofing compounds. 

Ammonia, at ordinary temperature, is a colorless gas of well 
known odor and sharp biting taste. It is usually met with in the 
arts in watery solution, the specific gravity of which varies with 
the amount of ammonia gas dissolved. The strongest, sometimes 
called caustic ammonia, contains 32.5 per cent, of the gas, and 



152 ACIDS AND ALKALIES. 

has a specific gravity of .875. Ordinary commercial ammonia 
has a percentage of 9.5 and a specific gravity of 0.96. The weak- 
est usually has a percentage of 5.5 and a specific gravity of .978. 
Ammonia has a powerful solvent action upon sulphur, is alkaline 
in its nature, and very volatile, so that much care is requisite in 
handling it. It has long been known to have a preservative effect 
upon India-rubber; for example, low grade African rubbers are 
often treated with Ammonia to neutralize the smell, and also to 
toughen the rubber. In the cold-curing process a saucer of Am- 
monia put in the bottom of the vapor room will effectually neu- 
tralize the fumes of chloride of sulphur. It is also advised to 
wash vulcanite that has begun to perish with an Ammonia solu- 
tion. Soft rubber goods also are preserved, according to Dr. 
Pol, by the immersion for an hour in a solution made of i part of 
ammonia, and 2 parts of water. 

Sievier dissolved India-rubber in Ammonia, leaving it in a 
closed vessel for a long time, after which he heated the solution 
and distilled the Ammonia gas in cold water. Concentrated liquor 
of Ammonia is added to milk of the rubber tree to preserve it for 
transportation. Where vegetable fibers are reduced to cellulose 
and mixed with India-rubber, the rubber is first steeped in Am- 
monia and then dissolved in some suitable solvent. Newton mix- 
ed Ammonia with India-rubber and Gutta-percha, and then treat- 
ed the gum with chlorine, making a white hard compound which 
he claimed would stand all varieties of climates, acids, greases, etc. 

Aniline. — A colorless oily liquid, manufactured chiefly from 
coal tar or nitrobenzene. It is a base from which the brilliant 
aniline dyes are made. Aniline used by Parkes in the manufac- 
ture of Parkesine, is also a solvent for Gutta-percha. 

Arsenate of Potash. — It is a very soluble compound of 
arsenic with potash and forms what is known as Fowler's solu- 
tion. In the dry state it is a white powder soluble in alcohol up 
to 4 per cent. Arsenate of Potash was used by Forster, among 
his earliest experiments, to partially vulcanize a compound made 
up of India-rubber and shellac. 

Barium Chloride. — A white crystaline powder, insoluble in 
alcohol but soluble in hot water, 78 per cent., and in cold 38 per 
cent. Its specific gravity is 3.05. It is not of great technical im- 



BARIUM CHLORIDE— BORAX. 153 

portance, its principal value being that of a test for sulphuric acid. 
To makers and users of sulphurets it affords a ready means of 
determining the presence of free sulphuric acid, so liable to occur 
in these bodies and so injurious to rubber compounds when pre- 
sent. A suspected sulphuret should be boiled for a moment with 
a little distilled water, the water filtered off, and a drop or two 
of a solution of Barium Chloride added; a white cloudiness that 
will settle in the form of a white powder proves the presence of 
sulphuric acid and such a sample should be rejected. Barium 
Chloride is a powerful poison. Used with size and acid resin as a 
shower-proof mixture. 

BisuLPHATE OF PoTASH. — A white powdcr obtained as a by 
product in chemical manufacturing. Soluble in twice its weight 
of cold water, and in half its weight of boiling water. It contains 
sulphuric acid so loosely held in combination that it is driven off 
upon heating. Its specific gravity is 2.16. (See Potash.) 

Bichromate of Potash. — The principal compound of chro- 
mium, which occurs in the form of orange red crystals, that are 
soluble in water and are largely used in dyeing. Mixed with sul- 
phuric acid, it is used in bleaching palm oil and other fats. Bi- 
chromate of Potash is used in vulcanizing the compound known 
as elastic glue; also used in Christia gums. 

Bleaching Powder. — See Chloride of Lime. 

BoRAcic Acid. — This is found native in the vapor which 
arises from certain volcanic rocks in a saline incrustation in vol- 
canic craters and in combination with borax. It appears in the 
form of pure white leathery crystals. Boracic Acid is used with 
tungstate of ammonia, Kauri, borax, and India-rubber in the pro- 
duction of the woodite fireproof compositions. 

Borax, or Biborate of Soda. — Sometimes also called tincal ; 
a compound of soda and boracic acid. The purified commereial 
article contains about 47 per cent, of water of crystal ization and is 
usually in the form of large odorless crystals, or a white powder 
obtained by grinding. The crystaline form has a specific gravity of 
1.69. Borax is quite soluble in water, but not in alcohol or any of 
the common solvents for rubber. At a moderate heat Borax loses 
water, and separates as a spongy mass called calcined borax, while 
at a higher heat it melts into what is known as borax glass. Im- 



T54 ACIDS AND ALKALIES. 

mense deposits of it are found in the United States, and it is also 
found in India, Hungary, and other parts of the world. A good 
waterproof cement is made of a mixture of Borax and shellac boil- 
ed in water. Borax, or a solution of biborate of sodium, has the 
property of dissolving many resins. Lascelles-Scott describes the 
manner in which an emulsion of rubber may be preserved by a 
Borax solution. To a solution of rubber, in any one of the com- 
mon solvents, a small portion of alcohol is added. This is mixed 
with a 2-5th saturated solution of Borax, previously heated from 
120° to 140° F. This is agitated until the temperature has cooled 
down to the temperature of the air. From 3^^ per cent, to 4^ per 
cent, of India-rubber should be present in the fluid when finished. 
A higher strength quickly separates and sometimes causes the 
entire quantity to coagulate. Madagascar or Sierra Leone rub- 
bers are advised for Borax solutions. Solutions of borated rub- 
ber are adapted for waterproofing and for preserving mats, ma- 
rine bedding, etc. Borax is also advised for preserving rubber 
milk from coagulation. It is also an important ingredient in the 
water varnishes used for luster finish, for surface coats, army 
blankets, etc. ; is used in waterproofing compounds composed of 
rubber, boracic acid, Kauri, tungstate of ammonia ; mixed with 
Gutta-percha and shellac, it was used by Hancock as an insulat- 
ing material. 

Carbolic Acid, also known as Phenic Acid, is obtained chief- 
ly during the destructive distillation of coal. The liquid has a 
hot burning taste, and is largely used for its antiseptic qualities. 
If white crystalized carbolic acid is added to the paste from which 
matrices in rubber stamp making are manufactured, it preserves 
the mixture for a long time. Carbolic Acid is used as a preserva- 
tive of rubber sap, where it is coagulated by the process employed 
by The Orinoco Co., in Venezuela. Carbolic Acid has also 
been used in connection with a little ammonia to increase the elas- 
ticity of low grade African gums, being used as a solution before 
the gums are washed. It is also used for treating fabrics, such 
as hose linings for fire and mill hose, to prevent deterioration and 
rotting. Used in certain fiber-made substitutes. 

Carbonate of Ammonia, obtained during the dry distilla- 
tion of bones, is a white crystaline powder of very penetrating 



CARBONATES— CAUSTIC SODA. 155 

smell, from which quality it takes its popular name of smelling 
salts. Exposed to the air, it yields ammonia and absorbs water, 
becoming superficially converted into bicarbonate. It is used in- 
dustrially for the removal of grease from cloth and cleaning 
woolen fabrics. Carbonate of Ammonia is used also in the manu- 
facture of sponge rubber, and in hollow work, where its expan- 
sive force is utilized to effectually mold the article. 

Carbonate of Soda. — Also called Sal-soda, washing soda. 
Prepared from cryolite, salt, etc. Its specific gravity is 1.45, when 
crystalized. The crystaline form contains 64 per cent, of water 
of crystalization, of which one-half is driven ofif by gentle heat- 
ing. It is a white crystaline substance and alkaline taste. It is 
found in the ashes of many plants, is produced artificially in large 
quantities from common salt, and is used as an alkaline agent in 
many chemical industries. Rubber, burnt umber, Japan, and a 
coloring matter are mixed with a certain proportion of Sal-soda 
for a waterproofing composition. Under the common name sale- 
ratus. Carbonate of Soda is used as follows: Instead of sunning 
surface goods, like rubber coats and blankets, they are often 
brushed over with a mixture of saleratus and powdered charcoal 
right after the stock leaves the calender. Sometimes the saleratus 
is left out, and only the charcoal is used. 

Caustic Soda. — The chief use of this, in the manufacture of 
rubber goods, is in the dissolving of sulphur that is formed on 
the surface of goods, and which is known as bloom. According 
to H. L. Terry, F. I. C, the bulk of the alkali supplied to rubber 
manufacturers in England is used in removing the sulphur from 
elastic thread. Of course it is used in treating tobacco pouches, 
fine sheet articles, and blacks, reds, or maroons, that should have 
a good clear color. The boiling of rubber goods is usually done 
in wooden tanks in which steam can be passed, and sometimes in 
slate tanks, as iron is attacked by the alkali. On good grades of 
rubber caustic soda has no action at all ; where a large quantity of 
resin is present, however, it may dissolve some of them, forming 
resinates of soda. Heavily compounded rubbers, whether they 
contain substitutes, gums, or compounds, unless they are abso- 
lutely inert, are also liable to be attacked through the dissolution 
of their ingredients. Camille describes a process whereby shoddy 



156 ACIDS AND ALKALIES. 

is treated with a solution of carbonate of soda in devulcanization. 
In this, the rubber is boiled several hours in a solution of taustic 
soda, the result being that it will sheet v/hen the process is com- 
pleted. Rostaing purified Gutta-percha by boiling several hours 
in caustic soda, or in a mixture of caustic soda and potash in . 
water. 

Catechu, or Cutch. — Known formerly as Japan earth. 
Made from the sap of an East Indian tree, and used chiefly in 
dyeing. Is very astringent, and is soluble in water. It appears 
in commerce in dark brown irregular lumps. Contains 40 to 50 
per cent, of a peculiar tannic acid. Used in packings and goods 
made from the whaleite formulas. Johnson^s artificial leather was 
made of catechu, rosin oil, linseed oil, turpentine, and starch, 
mixed with a little hot Gutta-percha. A number of other com- 
pounds, both with and without India-rubber, contain catechu, 
but chiefly those which were compounded from gelatine, starch, 
and gluten. Catechu is mixed with Gutta-percha in solution in 
order to make it harder. 

Caustic Ammonia. — See Ammonia. 

Caustic Potash, — As occurring in commerce, it is a white 
solid substance of the specific gravity about 2.5. It is hard and 
brittle, and very destructive to animal or vegetable substances. 
It rapidly takes up water from the air, and may be used to obtain 
a dry atmosphere in a confined vessel. It is also a greedy absor- 
bent or carbonic acid, becoming converted into the carbonate 
thereby. Solutions of potash should be clarified by allowing im- 
purities to subside. Its taste is bitter and acid and its smell un- 
pleasant. Alcoholic Caustic Potash is used in analysis of vul- 
canized India-rubber and was introduced by Henrichs, particu- 
larly to separate India-rubber from India-rubber substitute. 
Caustic Potash is mixed with flowers of sulphur for boiling draw- 
ing rolls, the potash making the rubber more solid, while the sul- 
phur gave a peculiar surface, making it better for drawing. Used 
in water solution to remove bloom from cured rubber. It is also 
used in certain substitutes for hard rubber, like voltit. Potash 
was early used in extracting the sulphur from ground vulcanized 
rubber. A percentage of it is used to-day in neutralizing the acid 
used in the chemical recovery of rubber. 



CHLORIDES. 157 

Chloride of Ammonium. — Also known as muriate or hy- 
drochlorate of ammonia, or sal-ammoniac. Obtained largely from 
gas works. Specific gravity 1.5. Usually occurs in small crystals 
of a sharp, saline taste. When dissolving in water a considerable 
reduction of temperature occurs, and this has rendered it valuable 
for cooling purposes. At temperatures above 212° F. it is com- 
pletely evaporated, and a decomposition occurs into ammonia 
and muriatic acid. It is used in certain packings in which iron 
filings are incorporated. 

Chloride of Calcium. — A crystaline substance containing 
about 50 per cent, of water of crystalization, which is lost on heat- 
ing to 392° F. The specific gravity is 1.6 1, and that of the dried 
form 2.21. Its extreme attraction for water makes it useful in 
obtaining a dry atmosphere in any closed receptacle. Its color 
is white, taste acrid and sharp. It absorbs ammonia readily and 
will give it up again on heating. It is used in bookbinders' ce- 
ments. 

Chloride of Lime. — Sometimes called bleaching powder, 
although this latter is a mixture of the chloride and hypochlorite 
of lime. Industrially, its chief use is for bleaching purposes, de- 
pendent upon the amount of chlorine it contains. Commercial 
bleaching powder is a white powder with a faint smell of peculiar 
character and gradually becoming moist on exposure to the air, 
while it gradually decomposes and absorbs water and carbonic 
acid. Even in closed vessels decomposition occurs, and some- 
times so suddenly and with such a rise of temperature that explo- 
sions occur. Hence it should always be used fresh and a guaran- 
tee obtained from the vendors (as is customary) of the quality of 
the article. Chloride of Lime is the liasis of a cold curing pro- 
cess known as Caulbry's (which see). Gutta-percha boiled in it 
and then mixed with rosin and paraffine is used in insulation. 

Chloride of Sodium (or common salt) has a specific gravi- 
ty of 2.3. It is a very stable compound, soluble in water at the 
ordinary temperature to the extent of 36 per cent., at the boiling 
point 39 per cent. At the freezing point water will take up 5^^ 
per cent, of common salt. It is used, as is well known, in coagu- 
lating many of the rubber saps. Salt is viewed with considerable 
distrust by ordinary manipulators of rubber. Payne, however, 



158 ACIDS AND ALKALIES. 

treated Gutta-percha scraps by boiling water, salt, and oil of vit- 
riol, to get a solution to which he added other gums and metallic 
oxides to get a waterproofing mixture. Cooley made artificial 
leather of Gutta-percha dissolved in resin oil, and added 25 per 
cent, or more of salt, to which he added starch or other saccha- 
rine substances. Salt, in the form of brine, is used in washing the 
compound known as tremenol as a last process. It is also used in 
shower-proofing compounds, in connection with paraffine and sul- 
phuric acid. 

Chloride of Zinc was known formerly as butter of zinc. It 
is formed by burning zinc in chlorine gas, or by dissolving it in 
hydrochloric acid, the solution being evaporated. The anhydrous 
form is a whitish gray mass which readily fuses, and can be sub- 
limed at a high temperature. It deliquesces on exposure to the 
air, and is readily soluble in water, the solution having a bitter 
taste, and acting in a concentrated state as a powerful caustic. 
One of the best processes ever known for reducing the fiber in 
recovering rubber was that in which this substance was employed 
instead of acid. A boiling solution of Chloride of Zinc was used 
in deodorizing by Brockedon, who also mixed it with Gutta- 
percha, adding sulphur and vulcanizing the gum. Hancock also 
subjected Gutta-percha for a moment or two to binoxide of nitro- 
gen, then immersing it in a boiling solution of chloride of zinc, 
which he claimed greatly improved its quality. 

Chromic Acid is not readily obtained in a free state, but 
forms many well-known salts, such as chrome yellow, for in- 
stance. It is analogous to sulphuric acid. Vulcanized rubber 
immersed in it at 140° F., remained a month, and was apparently 
unharmed. It is also used in the manufacture of the substitute 
known as corkaline. 

Citric Acid. — An organic acid that occurs in lemons, limes, 
and many other fruits. It is readily soluble in water, and has an 
intensely sour taste. Has been used in the coagulation of Balata. 
Vulcanized rubber immersed in it at 140° F., remained a month, 
and was apparently unharmed. 

Cream of Tartar. — A white crystaline substance with an 
acrid taste, a very common ingredient in baking powders. Is 
called also Potassium Bitartrate. Is made from purified tartar, or 



CREAM OF TARTAR— LIME. 159 

argol. Is used in artificial ivory made from resins in solution. 

Crystals of Soda. — See Carbonate of Soda. 

Cyanide of Potassium. — A white crystaline substance, very 
poisonous, of a sharp bitter taste. It is very easily decomposed, 
even on exposure to the air absorbing carbonic acid and yielding 
prussic acid, which gives the salt its peculiar smell of peach ker- 
nels. The vapors thus given off are very poisonous. Cyanide of 
Potassium was used by Brooman "to give clearness to the gum 
which was made from ground vulcanized rubber, which had been 
treated with alkalies and acids to remove sulphur and adulterants." 

Fluoride of Silicon is a colorless gas. What is used in the 
arts is a solution in water, forming a very sour fuming liquid, 
acting like a strong acid. It is easily decomposed and may be 
used for etching glass if allowed to evaporate upon it under heat. 
It is prepared from flints or silica in some such form as sand or 
powdered glass. Used in treating meerschaum and paper pulp 
which, combined with certain resins, forms an artificial ivory. 

Formic Acid obtains its name from the fact that it was first 
obtained from the red ant. It is a fuming liquid with a pungent 
odor, boiling at 212° F. It is now made from a mixture of 
starch, binoxide of manganese, sulphuric acid, and water. It has 
been suggested as an ideal precipitant for rubber milk. It is quite 
volatile, could be easily washed out, and would be found more 
beneficial to the rubber than many of the alkaline solutions now 
used. 

Hydrochlorate of Ammonia. — Another- name for Muriate 
of Ammonia or Sal-ammoniac. (See Chloride of Ammonium.) 

Hypochlorite of Lime. — One of the principal constituents 
of bleaching powder. It does not exist alone. (See Chloride of 
Lime. ) 

Hydrosulphuret of Lime. — Lime that has been treated 
with hydrogen sulphide. It is an offensive smelling substance, 
of a dirty greenish grey appearance, and is obtained in the process 
of purifying coal gas. It decomposes easily, giving off sulphu- 
retted hydrogen. It will absorb bisulphide of carbon and is solu- 
ble in alcohol. Its liability to oxidize should render it of ques- 
tionable use in compounding. It was used by Hancock in vulcan- 
izing India-rubber. 



i6o ACIDS AND ALKALIES. 

Hydrochloric Acid is known usually by its trade name of 
muriatic acid. It is also known as chlorhydric acid, and spirits 
of salt. It is one of the principal mineral acids. Used in the arts 
in the form of a watery solution, of which the strength varies 
from a specific gravity i.oi or 2° Beaume with 2.02 per cent, acid 
to 1. 21 or 26° Beaume, with 42.85 per cent. acid. Each .01 in- 
crease of gravity corresponds to 1° Beaume and 2.02 per cent, 
of acid. It is corrosive to the skin and attacks nearly all metals. 
It has no action on caoutchouc and very little on oxidized linseed 
oil if the acid be dilute. With soda and its compounds generally 
speaking it will form common salt and with metals it forms chlo- 
rides thereof. Hydrochloric acid, during the treatment of re- 
claimed rubber, turns whiting into chloride of lime. As the chlo- 
ride is more soluble than sulphate of lime much of it washes out 
during the vigorous cleansing that the rubber undergoes to re- 
move the free acid. Hydrochloric Acid, according to tests made 
by William Thompson, F. R. S., did not at all injure India-rub- 
ber, although it was kept in it at a temperature of 140° F. for a 
month. Concentrated hydrochloric acid has but little action on 
Gutta-percha, and tubing made from it is therefore largely used in 
chemical factories for running this acid from one vessel to an- 
other. Hydrochloric Acid is used in the manufacture of turpen- 
tine rubber, and in one of the last processes in the analysis of 
vulcanized India-rubber. In preparing a hard rubber compound, 
Austin G. Day used linseed, cottonseed, castor, and coal oils ; hy- 
drochloric and nitric acids ; bicarbonate of soda, muriate of tin, 
coal tar asphaltum, sulphur, and Gutta-percha. 

Iodide of Antimony. — A brownish red crystaline mass, 
which yields a cinnabar red powder. It is soluble in hot carbon 
bisulphide. Its specific gravity is 4.39. It was used by Parkes 
in vulcanizing India-rubber. 

Iodide of Zinc. — A very unstable substance. A white gran- 
ular powder, odorless and of sharp saline metallic taste. Chiefly 
used in medicine. It was used by Hancock to assist in the vul- 
canization of India-rubber. 

Liquor of Flint. — See Silicate of Soda. 

MiMO-TANNic Acid. — See Catechu. 

Muriate of Ammonia. — See Chloride of Ammonium, 



MURIATIC ACID— NITRIC ACID. i6i 

Muriatic Acid. — See Hydrochloric Acid. 

Nitrate of Lead. — A compound of lead and nitric acid con- 
taining 62.5 per cent, of lead. Its specific gravity is 4.58. It has 
an astringent metallic taste, crackles when heated, detonates when 
thrown on red hot charcoal, and takes fire when ground with sul- 
phur. Its color is white and it is largely used in dyeing and for 
making chrome yellow (which see). It is used with gums in the 
production of shower-proof mixtures with sugar of lead and 
alum. 

Nut-Gall. — An excrescence formed on the leaves of a spe- 
cies of oak called Quercus infectonia. It is used in the arts for the 
sake of the tannic acid it contains. There are three varieties in 
commerce — green, white, and black. The black and the green 
are the best. Those grown in warm countries are the best. Aleppo 
galls contain from 60 to 66 per cent, of tannic acid. There is a 
variety^ of nut-gall known as Chinese, imported from Japan, 
China, and Nepal. The gall is somewhat bean-shaped or is cover- 
ed with a yellow gray felt. It contains from 60 to 70 per cent, 
of tannic acid. Nut-gall is used in certain places instead of tan- 
nin, which see. 

Nitric Acid. — Chemically an oxide of nitrogen. Technically 
a strongly acid liquid consisting of an aqueous solution of the pure 
acid. Its action on different bodies is various. Some, like sul- 
phur, phosphorus, carbon, and many organic substances are easily 
oxidized. Tin and powdered antimony are rapidly converted into 
their oxides, while turpentine, if poured into the strong acid, is 
attacked with almost explosive violence with the evolution of light 
and heat. Straw or sawdust may become ignited if impregnated 
with this acid. Cotton wool is converted by it into gun cotton. 
Rubber immersed in Nitric Acid at a temperature of 140° F. was 
injured in a few hours, and in a few days its elasticity was de- 
stroyed, while at the end of the month it was reduced to a pulp. 
Nitric Acid attacks Gutta-percha very powerfully, and evolves 
suffocating fumes of a deep red color, the gum meanwhile being 
reduced to a pasty mass which afterwards dries and becomes very 
brittle. According to H. L. Terry, F. I. C, Nitric Acid of any 
strength has a very deleterious effect upon India-rubber, the action 
of the fuming acid being to form immediately an oxidized body of 



i62 ACIDS AND ALKALIES. 

a resinous nature. He holds, therefore, that the weaker acid also 
injures the India-rubber, although of course in a less degree. 
Nitric Acid is used in the treatment of leather cuttings to reduce 
them to a glutinous mass before being mixed with India-rubber, 
and is also used in making certain substitutes. 

Oil of Vitriol. — See Sulphuric Acid. 

Oleic Acid. — An acid found in certain animal and vegeta- 
ble oils, such as olive oil, sperm oil, etc. It has been used in cer- 
tain substitutes for hard rubber, like voltit, and by Hunt for re- 
covering waste vulcanized rubber under heat, methylated spirit 
being added later to precipitate the rubber, which was then wash- 
ed in weak caustic soda. 

Oxalic Acid occurs as transparent, colorless prisms, with a 
very sour taste, soluble in both cold and hot water. It is pro- 
duced by either the action of the hydrate of potash, or of nitric 
acid upon most organic compounds. It is very poisonous. Gutta- 
percha was cleansed by Lorimer's process by boiling in water mix- 
ed with this acid. 

Oxalate of Lime. — Quick lime slaked by water in which is 
oxalic acid is given this name. Used in certain Gutta-percha 
compounds. 

Permanganate of Potash occurs in dark red prisms of a 
greenish color which, when dissolved in water, gives a purple red. 
It is a decided oxidizer, and is used as a disinfectant. It is also 
called chamelon mineral. Used in certain artificial leathers 

Peroxide of Hydrogen. — This is a powerful oxidizing 
agent, largely used as a bleaching agent, and also as an antichlor 
for use after chlorine bleaching. It comes in the form of a color- 
less liquid, and has a specific gravity of 1.45. Neither the alka- 
line nor the acid solutions of this reagent seem to impair vul- 
canized India-rubber. In certain cases Peroxide of Hydrogen 
has been used in removing the bloom from rubber, which it does 
most effectively; besides, it seems to penetrate the surface of the 
rubber and dissolve the sulphur. It also has a curious effect on 
colors, brightening some reds wonderfully, dulling others, and 
rendering whites much whiter. One curious effect that it has 
upon India-rubber is to bring out any surface imperfections in a 
marked degree. 



PHOSPHATE OF SODA—SALICYLIC ACID. 163 

Phosphate of Soda. — A crystaline colorless substance con- 
taining 6q per cent, of water, which is given up on heating to 
248° F., leaving behind a dry mass. The commercial article fre- 
quently contains sulphate of soda as an impurity. The crystals 
have a specific gravity of 1.5, melt at 95° F., and are readily solu- 
ble in water. By long drying at 113° F. the water of crystaliza- 
tion may be entirely driven off. The presence of this material 
is called for in a certain compound for dental vulcanite, where it 
is incorporated with rubber, sulphur, and phosphate of lime, the 
idea being that less sulphur is required than in the ordinary com- 
pounds. 

Phosphoric Acid. — See Phosphorus. 

Potash. — This substance, a carbonate of potassium, is usu- 
ally met with commercially in small colorless crystals. It is pre- 
pared in a variety of ways and forms, the basis from which is 
prepared what is called caustic potash. Pearl ash is a crude form 
of potash mixed with the caustic variety and a sulphuret of potas- 
sium. Used in certain proofing compounds where low heat is re- 
quired for cure. It was used by Charles Hancock, mixed with 
water in a bath, to improve the quality of Gutta-percha. He 
found, by boiling the Gutta-percha in such a bath for an hour, 
that it did not oxidize in the open air as badly. An old-fashioned 
process for treating unvulcanized thread was to steep it in a hot 
solution of carbonate of potash, which greatly increased its 
strength. (See Caustic Potash.) 

Quick Lime is the impure oxide of calcium obtained by heat- 
ing or burning chalk, marble, or limestone, or any carbonate of 
calcium. Its well-known attraction for water renders it unstable 
but also valuable where dying qualities are desired. Blizzard 
claimed to be able to make a perfectly transparent rubber by treat- 
ing it with soda and water, in which was a little Quick Lime. 

Rennet is made from the inner lining of the true stomach 
of the sucking calf and gets its value from the gastric juice con- 
tained thereni. The membrane, after treatment, is salted and 
stretched out to dry. It is advised in the Vaughn process for 
coagulating Balata. 

Salicylic Acid is obtained from the creeping plant known as 
wintergreen. It is prepared from the oil of wintergreen (oil of 



i64 ACIDS AND ALKALIES. 

Gaultheria), which is distilled in large quantities in Luzerne 
county, Pa. It is soluble in the following proportions: i part 
of the acid dissolves in 450 of water, or 2.4 of alcohol. It melts 
at 312° to 314° F. Salicylic Acid was used in an artificial leather 
compound for reducing leather dust to a paste, after which it was 
mixed with glue under heat, and treated to an alkaline solution. 

Sal Ammoniac. — See Chloride of Ammonium. 

Salt. — See Chloride of Sodium. 

Saltpeter is niter or potassium nitrate. It is a crystaline 
substance, white, and having a saline taste, and is a very strong 
oxidizer. It is used in the manufacture of artificial elaterite. In 
Gridley^s process for recovering rubber, by exposing it to flame, 
saltpeter was added to remove the smell. 

Saleratus. — See Carbonate of Soda. 

Sal Soda. — See Carbonate of Soda. 

Soda. — See Carbonate of Soda. 

Sodium Hyposulphite. — A i per cent, solution is used for 
removing traces of chlorine where its presence is suspected in 
rubber. 

Soluble Glass (known also as waterglass) is a silicate of 
soda or potash. It is usually sold in solutions of varying density, 
the commonest being 33° and 66°, by which is meant that the solu- 
tion contains either one third or two thirds solid waterglass. 
Acids readily precipitate the silica from these solutions as a gela- 
tinous mass. It is used in certain shower-proof compounds and in 
compounds of the Algin (which see) type. 

Stearic Acid. — See Stearine. 

Sulphate of Alumina. — The active principle of alum. 
Often sold as concentrated alum. Occurs commercially as white 
square cakes, somewhat transparent, and capable of being cut 
with a knife. Readily soluble in water, and contains a small 
quantity of free sulphuric acid, potassa, and soda alum. Its spe- 
cific gravity is about 4; water of crystalization 48 per cent. Its 
composition indicates a usefulness in compounding sponge rub- 
bers. Used in linseed oil compounds, for wagon covers. (See 
Alum.) 

Sugar of Lead. — This is used in certain rainproof com- 
pounds, one of which is 16 parts of compounded rubber, 128 



SULPHATE OF COPPER— SULPHURIC ACID. 165 

parts of paraffine wax, i part of Sugar of Lead, i part of alum 
in powder. India-rubber compound contains no sulphur. Used 
also in artificial rubber and artificial ivory. (See Acetate of Lead.) 

Sulphate of Copper. — Sometimes called blue or Cyprus 
vitriol. Occurs in commerce in masses of large blue crystals hav- 
ing a specific gravity of 2.28, and containing 36 per cent, of water 
of crystalization, and a varying additional percentage of entangled 
moisture. Heated for some time at 212° F. all the entangled wa- 
ter may be driven off, together with four-fifths of the water of 
crystalization, the residue being a bluish white powder. Sul- 
phate of Copper is used in attaching rubber to iron during vul- 
canization. 

Sulphate of Soda occurs commercially in colorless crystals 
which deteriorate in contact with the air, and hence should be 
kept in well closed vessels. It contains a very large amount — 
nearly 60 per cent. — of water of crystalization, which is yielded 
on heating to 302° F. Its reaction is alkaline. Sulphate of Soda 
was used by Hancock in vulcanizing Gutta-percha. 

Silicate of Soda. — See Soluble Glass. 

Soaps. — Various kinds of soaps are used in rubber manu- 
facture. Pure Castile soap, for instance, is dissolved in rain wa- 
ter and made into a soft soap that is used to "slick" molds that 
the rubber, during vulcanization, may not adhere to them. Some 
manufacturers use by preference white soda soap made from 
caustic soda and olive oil. Resin soaps are also used in certain 
shower-proof compounds. A further use for soap is in the manu- 
facture of water varnishes for luster coats and blankets. A soap 
compound for wagon covers is made of 50 pounds of soap dis- 
solved in 15 gallons of water, heated to 250° F., to which is 
added 25 pounds of sulphide of zinc. A half pint of rubber dis- 
solved in olive oil by heat is added to each gallon of the above 
mixture. Whiting, lampblack, or coloring matters may be added. 
Vulcanized rubber, beeswax, resin oil, argillaceous earth, and al- 
kaline soap form the basis of SorePs substitute for rubber. 

Sulphuric Acid (called also Oil of Vitriol), when pure, is 
a colorless oily looking heavy liquid of a sharp, sour taste. It is 
very corrosive, and has a great attraction for water; hence wood 
and other organic bodies are charred by its depriving them of 



i66 ACIDS AND ALKALIES. 

their water. The specific gravity of the commercial acid is usu- 
ally about 1.83, or 66° Beaume, containing 94 per cent, of acid. 
Sulphuric Acid is used in the coagulation of Madagascar rubber. 
The Orinoco Co. are also said to coagulate India-rubber by mix- 
ing the milk of the Hevea with sulphuric and carbolic acid. Com- 
mercial Sulphuric Acid is said to coagulate 55 times its volume 
of gum, while the carbolic acid acts as an antiseptic in the juice, 
improving its keeping qualities. It is a question whether rubber 
treated this way is as good as that obtained by the smoking pro- 
cess. Rubber immersed in Sulphuric Acid at 140° F. remained a 
month and came out stronger, apparently, than when it went in. 
Sulphuric Acid is used in paste blacking, mixed with boneblack, 
vinegar, molasses, and caoutchouc oil. Concentrated Sulphuric 
Acid colors Gutta-percha broAvn, throwing off at the same time 
Sulphuric Acid fumes. Nevertheless, a paste of this acid and 
charcoal was added by Hancock to Gutta-percha to make it pli- 
able. Sulphuric Acid may be expected to attack vulcanized rub- 
ber compounds in which there are large proportions of chalk, lead 
oxides, or barytes. Sulphuric Acid is very largely used in des- 
troying the fiber found in ground waste rubber; indeed it is the 
basis of what is known as the acid reclaiming process. When 
thus used the acid turns whiting into sulphate of lime. 

Tannic Acid. — See Tannin. 

Tannin includes a number of substances, some of which are 
crystaline and others amorphous, with a marked astringent taste, 
and no smell. The solutions are acid, soluble in water and alco- 
hol, and yields precipitates with most metallic oxides. It is the 
active principle of oak bark, hemlock bark, catechu, and many 
other materials usually used for tanning hides. Pure Tannin is 
a light powder of a yellow greenish hue, soluble in water, alcohol, 
and ether. Its solution precipitates glue. It is used with sul- 
phate of alumina, waterglass, and glue in shower-proofing. Tan- 
nin has been claimed to be injurious to rubber, the reason being 
that rubber thread used in gorings is often destroyed at points 
close to its junction with the leather. It is more likely, however, 
that it is the oil or oleic acid that effects the destruction. Tannin 
was largely employed by Austin G. Day in many of his "kerite" 
compounds with excellent effect. It is also used in the manufac- 



TARTARIC ACID—TUNGSTIC ACID. 167 

ture of certain puncture fluids, together with glue and glycerine. 

Tartaric Acid is found usually in the form of transparent 
colorless prisms, which have an agreeable acid taste, are not af- 
fected by the action of the atmosphere, and are soluble in either 
alcohol or water. Nitric acid or peroxide of lead act upon Tar- 
taric Acid, turning it into formic and carbonic acid. This acid 
is very abundant in the vegetable kingdom, being found in many 
fruits. Used under Vaughn's patent in coagulating Balata. Vul- 
canized rubber immersed in Tartaric Acid at 140° F. remained a 
month, and was apparently unharmed. 

TuNGSTATE OF Ammonia. — A crystaline body which is very 
soluble in water and becomes covered with a white bloom on ex- 
posure to the air. Used with boracic acid, kauri, borax, and rub- 
ber in the production of the woodite fireproof compositions. 

TuNGSTATE OF SoDA. — Prepared commercially from wolfram 
and soda ash: usually contains about 14 per cent, water of cry- 
stalization; and is in the form of colorless crystals. Mixed with 
a solvent such as methylated ether, it is added to soluble gun 
cotton, castor oil, and gum copal, forming a substitute for India- 
rubber. 

TuNGSTic Acid is derived chiefly from wolfram, which is a 
tungstate of iron and manganese. Tungstic Acid is analogous to 
sulphuric and chromic acid. It has been used in connection with 
paraffine, gelatine, and metallic oxides in proofing compounds. 



CHAPTER X. 

VEGETABLE, MINERAL, AND ANIMAL OILS USED IN RUBBER COMPOUNDS 

AND SOLUTIONS. 

The use of oils in the rubber manufacture has kept pace fully 
with the use of gums, substitutes, and reclaimed rubber. The ad- 
dition of earthy or metallic or vegetable ingredients in dry mix- 
ing has rendered many a good rubber somewhat intractable — a 
fault which the right oil. has often rectified. As a rule, vegetable 
oils are chosen, as they are rarely harmful to the gum. Many 
mineral oils are also freely incorporated in certain compounds. 
Animal oils have always been viewed with more or less sus- 
picion, however, and with good reason, for manufacturers have 
constantly before them rubber goods that have lost their life and 
elasticity through contact with lubricants made of such oils and 
fats. Nevertheless certain of them may be and are used. The 
essential or volatile oils are used to a certain extent in rubber 
manufacture. These oils, as a rule, are liquids which give the 
peculiar odors of plants from which they are derived. Their use 
in rubber is to impart to it a pleasing odor. 

Aluminum Lanolate. — This is a product of French wool 
grease (which see), made by adding a solution of alum. After 
the addition of the alum, it falls in a brown precipitate. It is then 
dissolved in mineral oil, forming a jelly-like mass which is said to 
compound readily with either India-rubber or Gutta-percha, and 
is soluble in any of their solvents. It is possible that this may 
have some both softening and preservative influences on India- 
rubber, as is claimed, but it should be used with considerable 
caution. 

Anhydrous Paraffine Oil. — Water-free parafifine oil 
(which see.) 

Birch Oil. — The fine white bark of the birch tree 
yields a red oil, nearly one- fourth of yhich consists of the sap 
phenol, which gives the well-known odor to Russia leather. The 
residue, or green part of the birch, yields neither acid nor alkaloid, 
and forms with alcohol a fluid solution which, when once dried, 
is unacted on by alcohol. It is chiefly obtained from northern 

i68 



BIRCH OIL— CASTOR OIL. 169 

Europe and Siberia, and has recently been made also in Germany 
and Austria, where it is known as Jackten oil. This substance 
will unite with the most brilliant colors, and has been used in 
France for waterproofing textile fabrics. In connection with shel- 
lac, resin, and aniline, it is used in the form of a substitute for 
Gutta-percha in insulation. 

Blown Oils. — These are prepared by heating fixed oils in a 
jacketed kettle and blowing a current of air through the fluid. 
Under this treatment, oils become much more dense and also vis- 
cous; indeed, in many physical aspects, they resemble castor oil, 
but differ in that they can be mixed with mineral oils and as a 
rule are not easily soluble in alcohol. Blown oils made from lin- 
seed oil, rape oil, poppyseed oil, and cottonseed oil are sometimes 
used in. the manufacture of rubber substitutes instead of the raw 
oils. Known also as Thickened Oils, Base Oils, Soluble Castor 
Oil, etc. 

Bone Oil is obtained by the distillation of animal gelatinous 
substances, principally in the calcining of bones for the prepara- 
tion of boneblack. Its specific gravity is 0.97. It is sometimes 
called Dippel's Oil (which see.) 

Camphor Oil. — A liquid of a light reddish brown with a 
yellowish tint, a strong odor like camphor, and a bitter camphor- 
like taste. Its specific gravity is 0.94. Japanese oil varies in 
color from colorless, through pale straw, yellow, to black, and has 
a specific gravity of 0.898 for the colorless to 0.99 for the very 
dark. This oil is used in the manufacture of celluloid varnishes, 
paints, lampblacks, etc. It is used also as an adulterant for such 
oils as sassafras oil. It is one of the best solvents for resins, and 
dissolves 46 per cent, of rosin, 9 per cent, copal, and 35 per cent, 
of mastic. 

Caoutchouc Oil. — Made by digesting 55 parts of India- 
rubber in 450 parts of linseed oil. The only large use for this 
oil is in Germany, particularly in the army, where it was used for 
coating various articles to prevent their rusting. The following 
substances are found in Oil of Caoutchouc: Eupoine, butylene, 
caoutchoucine, isoprene, caoutchine, and heveene. 

Castor Oil. — A colorless or pale greenish transparent oil, 
very viscous and thickening on exposure to the air. It has the 



I70 OILS IN RUBBER COMPOUNDS. 

highest specific gravity of any known natural fatty oil — 0.958. 
It is adulterated frequently with resin oil and rape, linseed, and 
cottonseed oils, especially the "blown" variety. Used in cheap 
prooflngs without rubber with Kauri gum; also in collodion and 
rubber proofing. It is used in the production of substitutes like 
gum fibrine, and also with chloride of sulphur in producing amber 
colored substitute. 

Cholesterin. — See Lanichol. 

Cod Oil or Cod-liver Oil is obtained from the livers of cod- 
fish. Newfoundland and Norway are the principal manufactur- 
ing points. The finest is a very pale, clear, golden yellow, the 
color deepening to a brown in the second and third grades. Its 
specific gravity is 0.923 to 0.929. One part of oil is soluble in 
from 40 to 20 parts cold alcohol, or 30 to 17 parts hot alcohol. 
The lower grades are the more soluble. It is much adulterated. 
Is compounded with India-rubber, beeswax, linseed oil, litharge, 
and asphalt as a waterproofing for leather and with India-rub- 
ber, beeswax, and turpentine as a dressing for hides. 

Colza Oil. — See Rape Oil. 

Corn Oil (also known as Maize Oil). — Made from the seed 
of Indian corn, the plant being known botanically as Zea mays. 
There are two processes of manufacture: (i) in which the seed 
is pressed before it is used for the manufacture of starch, which 
produces oil of a golden yellow color, and (2) where it is recover- 
ed from the residue of the fermentation vats where the corn has 
been used in the production of alcohol. This oil is dissolved spa- 
ringly in alcohol, but very readily in acetone. The oil is almost 
Avithout drying powers. Neither boiling nor the addition of lead 
when boiling gives it definite drying properties. If it is heated, 
however, and a current of air passed through it, and manganese 
borate mingled with it, it dries after a fashion. It is largely used 
at present in the manufacture of what are known as Corn-oil sub- 
stitutes. 

Consolidated Oil. — See Stearine. 

Cottonseed Oil is made from the seeds of the cotton plant, 
usually the Gossypium herbaceum. The crude is of a ruby red 
almost black color. The refined is pale yellow and possesses 
a pleasant nutty taste. It is a semi-drying oil, and is rarely 



COTTONSEED OIL— FISH OIL. 171 

adulterated except when linseed oil is very cheap. On stand- 
ing it deposits stearine in waxy flakes. Much used in mak- 
ing substitutes for rubber. It is also used in the production of 
artificial elaterite, and with parafQne oil for canvas proofing. For 
Cottonseed blown oils see Blown Oils. 

Creosote Oil is a distillate from wood tar. It is an oily 
liquid with a smoky taste, and is antiseptic. It should be color- 
less but is usually yellow or brown, due to impurities or to expo- 
sure. The best is made from the beech. A similar oil is distilled 
from coal tar. Mixed with red oxide of mercury it has been used 
to coat the fabric of which cotton hose is made as a preservative ; 
with India-rubber and sulphur it has also formed an insulating 
compound for telegraph wires. It is used in some rubber works 
where it is arranged that the fumes of the naphtha are carried off 
into it, which it rapidly absorbs, to be later recovered by distilla- 
tion. 

EucALiPTiA. — A fragrant, refreshing volatile oil, twenty to 
forty times as strong a disinfectant as fluid carbolic acid. It is 
prepared from eucalyptus oil. 

Eucalyptus Oil. — An aromatic oil found in the leaves of 
the Eucalyptus globulus, in Australia. The odor of the oil is ex- 
tremely pleasant, smelling not unlike oil of verbena. This oil is 
said to be most advantageous, used in small quantities in connec- 
tion with solvents for India-rubber, as it tends greatly to accele- 
rate complete solution. It also breaks down refractory samples 
of the gum and renders all of the compound homogeneous. It 
is said that one-third of the time may be saved if from 4 to 6 per 
cent, of this oil is used in the solvent. It is especially good for 
low-grade gums. It has also great solvent power on all resins 
and gums, including India-rubber and Gutta-percha. With the 
addition of a little methylated spirit it will dissolve even Kauri 
gum, cold. It is also used in dissolving asphalt for photograph 
varnish. 

Essence of Petroleum. — Obtained during the refining of 
Petroleum, and known also as petrolatum, vaseline, petroleum 
jelly, etc. (See A/^aseline.) 

Fish Oil. — Obtained from all parts of the bodies of common 
fish by boiling. Fish whose livers yield oil commercially do not 



172 OILS IN RUBBER COMPOUNDS. 

give fish oil, and those bodies that yield oil, do not give liver oils. 
Principally prepared from Menhaden. Its specific gravity varies 
betwen .915 and .930. Fish Oil is used in the manufacture of the 
substitute known as volenite. It is used, however, only as a vehi- 
cle for carrying resin into the fiber, being afterwards wholly re- 
moved. 

French Wool Grease. — See Lanoline. 

Glycerine. — A clear liquid of oily consistency and sweet 
taste, without odor. When pure it has a specific gravity of 1.26. 
The Glycerine of commerce is a by-product of the soap manu- 
facture, chemical reaction occurring when the fat is treated with 
a caustic alkali, giving rise to a compound of a fatty acid and 
alkali to form a soap, while the Glycerine is at the same time lib- 
erated and goes into solution. Glycerine is not acted upon by 
oxygen, and therefore more closely resembles mineral oils, such 
as are used in rubber mixing, than it does the drying oils that go 
to make up substitutes. It has absolutely no solvent action on 
rubber. 

A recent German patent calls for the addition of Glycerine be- 
cause of its oil resisting qualities. In the compound used are 6 
pounds of rubber, and i pound of Glycerine, together with whit- 
ing, litharge, and sulphur. A soap made of Glycerine and an alka- 
line fluid is also used as a cleansing and polishing medium in the 
last stages of the manufacture of certain cut sheet goods. Gly- 
cerine combined with gelatine and borax has been used as a wash 
for both black and red rubber surfaces. 

Glycerine was the basis of a well-known deodorizing com- 
position for India-rubber, the other ingredients being of an alka- 
line nature. A bath of Glycerine has also been used for experi- 
mental work in vulcanizing India-rubber, and also for rubber 
stamp making. In this kind of work, the mold and its contents 
are immersed in the Glycerine so that the liquid just covers the 
top of the mold ; heat is then applied to the Glycerine, and the 
mold in turn becomes hot and the rubber vulcanizes. It is also 
used to a certain extent in good grades of white rubber, as it gives 
a softened eft'ect to the compound. Glycerine, in connection with 
glue, gelatine, molasses, and tannin, is used in the manufacture of 
puncture fluids for tires. It is also used in clothing compounds, 



GLYCERINE— LANOLINE. 173 

and in cellulose products like pegamoid. Used in rubber, a little 
of it increases the resiliency of the product. Another use for 
Glycerine is to prevent fabrics from mildewing. The fabric is 
coated with it before being frictioned. 

Japan Wax. — A white or pale yellow vegetable fat, with a 
specific gravity of 0.97 to 0.98. It is used in wax matches, 
candles, and for adulterating beeswax. A special use for it, that 
has arisen within the last few years, is in the manufacture of cra- 
venette cloths. 

Lallemantia Oil is obtained from the seeds of the Lalle- 
mantia iherica, a plant cultivated in Russia. This is one of the 
best drying oils, being said to surpass even linseed oil, but its 
chief use is for illuminating purposes. In Europe it is said to 
have been used instead of linseed oil in rubber substitutes. 

Lanichol. — A product of lanoline (which see), made from 
the oil of sheep's wool. It combines with Gutta-percha and India- 
rubber in any proportion to a perfectly homogeneous mass. This 
grease does not oxidize and is wholly antiseptic. It has no smell, 
and is impervious to the action of alkalies or to dilute sulphuric 
acid. It is said that, used in connection with Gutta-percha, the 
melting point is considerably raised, while it does not diminish 
the insulating property. An insulating compound given is 50 
parts by weight of Gutta-percha, 30 parts of India-rubber, 20 
parts Lanichol. The inventor claims that it renders Gutta-percha 
less liable to oxidation, improves its elasticity and tenacity, and 
diminishes its liability to become sticky. Patented in the United 
States and Great Britain by Robert Hutchinson. 

Lanoline is also known as wool grease, recovered grease, 
and brown grease. It is the natural grease found in sheep's wool 
and recovered from it while the raw wool is being prepared for 
spinning. A similar grease, made from scoured woven goods, is 
known as Yorkshire grease. It is a thick yellow or brown offen- 
sive smelling greasy paste. Commercial Lanoline is lighter color- 
ed and consists of about 80 per cent, of pure wool fat and 20 per 
cent, of water. It possesses in a remarkable degree the property 
of taking up water without losing its vaseline-like consistency. 
Is largely used in ointments. 

Lanoline, mixed with India-rubber, works up into an exceed- 



174 OILS IN RUBBER COMPOUNDS. 

ingly sticky mass, and is used as a medicinal plaster. It is said 
that, while it possesses the adhesive properties of the regular 
plaster, Lanoline takes up the medicament, and while very sticky 
can be readily removed from the skin. It is used for the purpose 
of softening India-rubber, and was advised for use in tires, as it 
was said to soften the compound, and to keep the tire from decay, 
and from consequent surface cracking. It was also said to be 
used in boot and shoe work. 

Lard Oil is prepared by the cold pressing of lard, which, of 
course, is the fat of the hog. It is a colorless, limpid liquid, al- 
though poorer grades are brown. Its specific gravity is 0.915. It 
is frequently adulterated with rape oil and cottonseed oil. Lard 
Oil, mixed with powdered pumice stone into a thick paste, is used 
for polishing hard rubber. 

Linseed Oil is pressed from the seeds of the flax plant 
(Linum usitatissimum) , grown chiefly in India and Russia. The 
trade recognizes two qualities of Russian seed — yielding the 
Black sea Linseed Oil, and the Baltic Linseed Oil — while that 
oommg from India is known as East India oil. Of these, the 
Baltic is the best, and the East Indian the poorest in quality. The 
two lower grades are not up in quality for the reason that the 
Black sea seed contains a certain amount of hemp-seed, while that 
from India is usually mixed with rape, cameline, and mustard 
seeds. The oil which is expressed from these seeds is of a golden 
yellow color, with a peculiar taste and odor. Linseed Oil becomes 
easily rancid in the open air, but when spread in thin films dries 
into an insoluble substance which has been called linoxyn. Lin- 
seed Oil is adulterated sometimes by fish or mineral oils, and by 
resin oils. Old tanked Linseed Oil is used in the preparation of 
what is known as boiled oil ; that is, it is heated in a high tempera- 
ture that it may more rapidly dry when used in varnish. This 
drying process is hastened by the addition of manganese dioxide, 
litharge, etc. Boiled Linseed Oil is much darker than raw oil, 
having a brown red shade. It is also much more viscous and has 
a higher specific gravity. Boiled oil is adulterated in the same 
manner as is raw Linseed Oil, the adulterants being resin oils, 
resin, and mineral oils. 

In rubber compounding Linseed Oil is very often used. A 



LINSEED OIL—NEATSFOOT OIL. 175 

very simple formula for waterproofing canvas is India-rubber, 
litharge, sulphur, and Linseed Oil. It is also used in rubber var- 
nishes, to a certain extent in molded goods, and quite largely in 
hard rubber compounding. It is used in the manufacture of rub- 
ber substitutes, and is well known as it is the basis of a great 
many of the vulcanized oil substitutes. Linseed Oil that is in- 
tended for mixing in linoleum is exposed to the air until it is 
thoroughly oxygenated. In this state it is insoluble in alcohol, 
chloroform, ether, and ordinary solvents. 

Lithographic Varnish. — This is obtained by boiling lin- 
seed oil at a temperature higher than that at which boiled oil is 
prepared, nor are dryers added during the boiling. It is a per- 
pectly clear, transparent substance, the best quality being nearly 
as light as raw linseed oil. There are two ordinary grades of 
Lithographic Varnish. One is known as "burnt oil,"* which is ob- 
tained by bringing raw linseed oil up to its flash point, and allow- 
ing it to burn until the required thickness is reached, it being con- 
stantly stirred meanwhile. "Oxygenated oil" is a linseed oil var- 
nish made by treating the oil with oxygen in jacketed kettles, 
heated by steam. The product is as light colored as raw linseed 
oil, but heavier. It is also more readily soluble in alcohol, and 
has marked drying powers. 

MiRBANE Oil. — See Nitrobenzene. 

Manganated Linseed Oil is used in certain rubber com- 
pounds where more of a drying effect is needed than is found in 
the raw linseed oil. It is linseed oil that has been boiled with 
peroxide of manganese to increase its drying qualities. (See 
Boiled Oil.) 

Mustard Oil. — Black Mustard Oil is obtained from the 
seeds of the Sinapsis nigra. It possesses a mild taste, is of a 
brownish yellow color, and in its chemical composition closely re- 
sembles rapeseed oil. It is a by-product and is largely used in soap 
making. White Mustard Oil is made from the seeds of the Sina- 
pis alba. It is of a yellow color, and is almost identical with black 
Mustard Oil. Both of these oils have been used in the manufac- 
ture of rubber substitutes. 

Neatsfoot Oil. — A pale, yellow, colorless oil, obtained from 
the feet of oxen by boiling in water. It has a smooth pleasant 



176 OILS IN RUBBER COMPOUNDS. 

taste. On standing it deposits stearine. It is largely adulterated 
with cheaper animal or vegetable and even mineral oils. Neats- 
foot Oil, mixed with Gutta-percha, tallow, sweet oil, and oil of 
thyme, is used as a rust preventative. It is used in connection 
with beeswax. India-rubber, and Burgundy pitch in a composi- 
tion for dressing leathers or hides. 

Nitrobenzene (also called "oil of mirbane" and "imitation 
oil of bitter almonds") is a yellow aromatic liquid produced by 
the action of nitric acid on benzene. It is used in perfumery and 
turned out in great quantities during the manufacture of anilines. 
It is used also in certain insulating compounds in connection with 
asbestos, powdered glass, vulcanized rubber, castor oil, resin oil, 
and celluloid in solution. 

Oil of Lavender has no perfume when new, but develops 
it on being exposed to the air. It is distilled from the flowers of 
the Lavandula vera, and is used sometimes to deodorize rubber 
goods. 

Oil of Lemon is obtained from fresh lemon peel. A very 
volatile yellow or colorless oil; specific gravity 0.858; soluble in 
bisulphide of carbon, and absolute alcohol ; often adulterated with 
fixed oils and alcohol; dissolves sulphur, phosphorus, resin, and 
fats ; used to deodorize certain proofing compounds, cologne 
sometimes taking its place. 

Oil of Orris^ or Orris Oil, is found commercially and is 
prepared from the root. It is lighter than water, and of the con- 
sistency of butter. Melts at 100° F., and is miscible with alcohol. 
Its odor is like that of violets. Is used in rubber as a deodorizer. 

Oil of Peppermint. — A greenish yellow colorless oil, be- 
coming reddish with age; of a strong and aromatic odor; and 
warm, camphor like, very pungent taste; specific gravity from 
0.902 to 0.920 ; used in fine goods for its odor. 

Oil of Rosemary. — An essential oil of the specific gravity 
0.896. Colorless and having the odor of rosemary. Used with 
India-rubber, paraffine, and spermaceti in waterproofing com- 
pounds, and, where rubber is present, to neutralize its odor. 

Oil of Tar. — An oil distilled from tar. It is a mixture of 
several lighter oils, and is made up of liquid hydrocarbons which 
hold in solution small quantities of anthracine, naphthaline, and 



OIL OF TAR— PALM OIL. 177 

paraffine. It is sometimes used for mixing with lubricating oils, 
and for coating bags that are to hold alkaline earths, the interior 
of the bag being washed with chloride of lime. The Earl of Dun- 
donald recommended Oil of Tar as a coating for rubber, claiming 
that it had a preservative effect. It is also used in compounds 
for surface clothing. 

Oil of Thyme (also called Origanum Oil) is extracted from 
the flowers and leaves of the Thymus vulgaris. It is yellowish red 
in color ; its specific gravity is 0.92 ; and it has a pungent taste ; 
it is used to disguise the odor of ale cements. 

Oil of Wormwood. — A pungent essential oil distilled from 
the Artemisia absinthium ; employed at an early day to deodorize 
spirits of turpentine when used in rubber. 

Oleargum. — A black viscid liquid of an oily nature used as 
a dull finish wash for rubber boots. Its composition is a trade 
secret. 

Oleum Succini. — The same as Oil of Amber (which see) ; 
used in the manufacture of soap substitutes. 

Olive Oil is expressed from the fruit of the olive tree, prin- 
cipally in the countries of Europe bordering on the Mediterra- 
nean. Its specific gravity is 0.916. It is adulterated frequently 
with cottonseed oil. Olive Oil is used in taking impressions from 
type-faces in the matrix in which rubber type is cured. Mayall 
suggested the mixing of Olive Oil with clay until it formed a 
soft putty, and then incorporating it with the India-rubber, the 
proportion being ^ pound of oil to 30 pounds of gum. The use of 
the oil enabled the goods to be more largely adulterated; he also 
used Olive Oil in connection with devulcanized rubber, not as a 
solvent, but because he claimed that it combined with the gum 
and improved its quality. Olive Oil is also used in hard rubber 
compounding. Rubber is sometimes heated up in Olive Oil mixed 
with zinc, soap, and borax for a proofing solution. It is also used 
in the manufacture of pegamoid. 

Palm Oil is obtained from the fruit of various species of 
palm, principally from the west coast of Africa, and is known in 
commerce under as many names as there are ports of shipment. 
It is expressed in a very rough fashion by the natives, who stir 
the palm kernels in holes in the ground until fermentation sets in 



178 OILS IN RUBBER COMPOUNDS. 

and the oil rises to the surface. They also sometimes press the 
oil from the fresh fruits. The harder grades of Palm Oil are 
yielded by the former procees, the latter giving the finer oils. 
Palm Oil varies in consistency. Its specific gravity is 0.945; its 
color yellow to reddish ; its odor that of violets. It yields a soap 
readily with alkalies and dissolves in ether and in alcohol of 0.848 
specific gravity. Palm Oil is very rarely adulterated, unless it is 
done by the native gatherers, who sometimes add sand as a make- 
weight. Commercially, where sand and water together exceed 2 
per cent., an allowance is claimed from the seller. 

White Palm Oil is that which has been bleached by heated 
chemicals or exposure to the air. "Lagos oiP has about the same 
consistency as butter, while "Congo oiF^ is as thick as tallow. 
Palm Oil is used largely in the manufacture of mechanical and 
dry-heat goods, chiefly to enable dry ingredients to mix more 
easily with India-rubber. It has also been used in the recovery 
of waste rubber by the mixing of the finely ground rubber with 
it and exposing the mass to a heat of 572° F. Palm Oil residuum 
is used in connection with resin oil as an insulator. Palm Oil is 
also used in the production of artificial elaterite. 

Paraffins Oil is a petroleum product; it is also prepared 
from coal tar and wood tar. It is a waxy substance of a white 
color, much resembling spermaceti. It is used chiefly as a lubri- 
cant, and is not acted upon by most of the chemical reagents. 
Parafline Oil mixed with cottonseed oil is used in certain canvas 
proofings. 

Petroleum Oil (also known as Rock Oil) is a dark, ill 
smelling liquid, obtained from wells sunk in oil-bearing sands. 
Some Russian oils, however, are colorless. White Rangoon oil 
contains so much paraffine as to have the consistency of butter. 
The specific gravity of American petroleum varies from 0.8 to 
0.85 or 0.9. 

Petroleum Paraffine. — See Vaseline. 

Petroleum Jelly. — See Vaseline. 

Petrolatum. — See Vaseline. 

Poppysefd Oil is obtained by pressing the seeds of the com- 
mon poppy (Papaver somniferum). Commercially there are two 
grades: (i) white Poppyseed Oil and (2) red Poppyseed Oil. 



POPPYSEED OILSTEARINE. 179 

I'his oil has a pleasant taste and no odor ; it is rarely adulterated 
v/itli other oils, although occasionally sesame oil is found in it; 
it is an excellent drying oil, and its lower grades are used in the 
manufacture of soaps ; its use in the rubber industry is chiefly 
in the manufacture of substitutes. 

Rapeseed Oil (also know as Colza Oil) is a pale yellow in 
color, with an unpleasant harsh taste. Its specific gravity is about 
{),9i6. It is largely adulterated with both vegetable, mineral, and 
fish oils. It is obtained from the seeds of the Brassica campestris, 
and of several varieties of this genus which are cultivated. Ame- 
rican oils from all of these are termed colza oil, or rape oil indis- 
criminately. In Europe, however, rape is one kind of oil and colza 
is another. There is also what is called the summer oil and the 
winter oil, a distinction which is of no interest to rubber manu- 
facturers. Rape oil is hardly a semi-drying oil, nor is it yet a non- 
drying oil, but about half way between the two. It is used in the 
manufacture of certain rubber substitutes. Mixed with India- 
rubber it has been used as a somewhat costly mixture for lubricat- 
ing machinery. 

Rosin Oil. — Made by subjecting resin to destructive distil- 
lation. The resultant oil is heavier than mineral oils, and its 
chemical composition is quite involved. It is largely made up, 
however, of hydrocarbons, with a certain amount of resin acids. 
Used in making a waterproof solution, by the addition of Japan 
wax and gum thus, in the manufacture of a solution for treating 
hides and leather. Used also in compounds for calking ships in 
which India-rubber has a part, and is an important ingredient in 
the manufacture of guttaline. 

Russian Mineral Oil. — Petroleum from the Baku oil wells 
in Russia. 

Shale Oil. — Chiefly produced in Scotland from a dark, coal- 
like looking material called shale. It is similar in nearly all re- 
spects to petroleum oil. Used with asphaltum in certain insulat- 
ing compounds. 

Sludge. — The brown or black residue obtained in the refin- 
ing of petroleum after all the lighter oils have been distilled off. 
Known also as Petroleum Residuum. (See Sludge-oil Resin.) 

Stearine. — An important ingredient in animal and vegeta- 



i8o OILS IN RUBBER COMPOUNDS. 

ble fats. It is quite solid, and increases the hardness, and raises 
the melting point of fat. Commercially, Stearine is also known as 
stearic acid. It is an important element in the manufacture of 
cravenettes, where it is used with ozocerite, beeswax, paraffine, 
and Japan wax. 

Tallow. — Beef tallow, when fresh, is almost white, free 
from disagreeable odor, and almost tasteless. On the other hand, 
foreign tallow runs from white to yellow and is often quite ran- 
cid. Tallow is often adulterated with resin oil, cocoanut oil, cot- 
tonseed oil, and paraffine wax. It is used in non-drying cements 
in connection with slaked lime and India-rubber. In connection 
with India-rubber it is also used in the production of what was 
known as Derry's waterproof harness oil, which was made of 
India-rubber, Tallow, seal oil, and ivory black. An etching var- 
nish is made of Gutta-percha, turpentine, beeswax, and Tallow. 
A small amount of this was used by Hancock in compounding 
for softening Gutta-percha. It is used with Gutta-percha in shoe- 
makers' wax, and also in certain proofing compounds with India- 
rubber, pitch, and linseed oil. Mixed with India-rubber, beeswax, _ 
and linseed oil. Tallow makes an excellent dressing for leather. 

Turpentine was used in one of the earliest formulas in the 
manufacture of devulcanized rubber. (See Spirits of Turpentine.) 

Vaseline is the purified residue from the distillation of pe- 
troleum. Its specific gravity is .875 to .945. It is insoluble in 
water, barely soluble in cold, but soluble in boiling absolute alco- 
hol, and in ether, bisulphide of carbon, oil of turpentine, benzine, 
and benzol. It is the basis of a cheap waterproofing process, the 
other ingredients being silicate of soda, alum, and hot water. 
Vaseline is used quite often in general compounding for its soft- 
ening effects. It is also combined with menthol and gum alibanum 
in the manufacture of porous plasters. Vaseline has been used 
in the manufacture of substitutes similar to ruberite. 

Vulcanized Oil. — See Rubber Substitutes. 

Walnut Oil. — Cold drawn oil is very fluid, almost colorless, 
and of an agreeable nutty flavor. Hot pressed oil has a greenish 
tint and an acrid taste and smell. Is used in rubber substitutes, 
particularly in those in which peroxide of lead appears as a dryer. 

White Drying Oil. — Bleached linseed oil. 



CHAPTER XI. 

SOLVENTS USED IN INDIA-RUBBER PROOFING AND CEMENTING AND 
IN COMMERCIAL CEMENTS. 
The beginnings of the manufacture of India-rubber consist- 
ed in putting the gum in solution; and it was a considerable 
time before the discovery of the present processes of dry mixing, 
which are employed in the production of the greater part of the 
rubber goods now made. There are certain lines, however, where 
the use of solvents is still both necessary and economical. In the 
mackintosh manufacture, for instance, the rubber is in almost 
every instance spread in the form of solution, as a thinner coat 
can be spread in this way, offsetting the cost of the solvent. Many 
sheetings in various colors that, only a few years ago, were calen- 
dered, are now coated by the means of solution. In the making 
up of almost all lines of rubber goods, certain cements are neces- 
sary, and these are ordinarily made in the factory that produces 
the goods. The cements that are sold in bulk, such as channeling 
cements, for leather shoe manufacturing, as well as cements that 
are sold in smaller packages to repair men in the cycle industry, 
all consist of rubber and analogous gums treated with some suit- 
able solvent. Before discussing the ordinary and the extraor- 
dinary solvents that interest the rubber manufacturer, it may be 
well to consider what the various solvents can do. 

The following tables showing the solubility of India-rubber 
are of exceeding interest, therefore. The first, which is taken 
from the Journal of the Society of Chemical Industry, is a table 
of the solubility of masticated caoutchouc in solvents : 

Ceara Para Sierra Leone 

lOo parts of : Rubber. Negroheads. Rubber. 

Ethyl ether 2.6 3.6 4.6 

Turpentine 4.5 5.0 4.6 

Chloroform 3.0 3.7 3.0 

Petroleum benzene 4.4 5.0 <^' 

Carbon bisulphide 0.4 None. None. 

Hoffer gives, as a result of his individual experiments, the 

following table of solutions, the samples in each case being 100 

parts of well-dried India-rubber: 

181 



i82 SOLVENTS FOR RUBBER. 

In bisulphide of carbon 65 to 70 

In benzol .... 48 to 52 

In oil of turpentine 50 to 52 

In caoutchine 53 to 55 

In ether 60 to 68 

In camphene 53 to 58 

The great differences between various grades of rubber have 
been found to be due, as much as anything, to the amounts of 
resins that are to be found in them. As these resins are soluble, 
and in some cases can be removed, it is important that rubber 
manufacturers not only appreciate their presence, but, where it is 
practicable, dissolve them out. These resins, according to Las- 
selles-Scott, who furnishes the following valuable table, consist 
of abietic acid or some other similar body : 



Normal Resin Normal Resin 

Description of (soluble in Description of (soluble in 

Rubber. 85 p. c. Alcohol). Rubber. 85 p. c. Alcohol) 

Para 91 Ceara 1.16 

Para 60 Assam 6.45 

Para 1.62 Assam 4.88 

Para 1.14 Burma 5.20 

Para 85 Rio 3.37 

Madagascar 4.06 Africa (various) 8.23 

Madagascar 5.22 Africa (various) 10.60 

Madagascar 2. 84 Africa (various) 6.71 

Colombia 3.40 Mangabeira 8.43 

Colombia 2. 11 Origin unknown 11. 14 

Ceara 2.33 Origin unknown 7.27 

Ceara i. 80 Origin unknown 16.56 

In some of them oxygen is a component part, and they are 
all soluble in alcohol of 85 per cent, strength and upwards. It 
will be noticed from this table that Para rubber has the least per- 
centage of resin, and, of course, is the most valuable. The sam- 
ples containing the largest proportions of resin were unmistaka- 
bly adulterated with other gums during collection. 

C. O. Weber gives the percentages of resin in a number 
of samples of rubber as follows: 

Grade of Rubber, '^Res^n"*' Grade of Rubber. ^^e^tn!' 

Para (fine) 1.3 Sierra Leone 9.7 

Ceara 2.1 Assam 11.3 

Colombian 3.8 Mangabeira 13. i 

Mozambique 3.2 African ball No. i 22.8 

Rio Janeiro 5.2 African ball No. 2 26.1 

Madagascar 8.2 African iiake 63.9 

Acetone is a colorless mobile liquid, with a very unpleasant 



ALCOHOL. 183 

taste and peculiar odor, and outwardly resembling alcohol. It is 
a good solvent for organic substances, and for many gums and 
resins. When recovered from wood spirit, it is distilled from 
the calcium chloride compound, generally with methyl alcohol. 
It has a specific gravity of 0.802. Acetone is the solvent used in 
the preparation of linoxin. 

Alcohol, when pure, is a colorless, thin, mobile liquid, of a 
somewhat disagreeable smell, burning taste, and specific gravity 
0.792. What is known as absolute alcohol is that which has been 
deprived of all water. Its specific gravity is 0.795. It eagerly 
absorbs water, and, as it becomes more dilute, its specific gravity 
rises ; alcohol of 60 per cent, has a specific gravity of .883. There 
are a number of forms of alcohol used in the arts. Methylated 
spirit is a form having the lowest boiling point of the group of 
alcohols ; rectified spirit is a term for alcohol of 95 per cent, and 
specific gravity .806 ; fusel oil is a complex mixture of alcohol and 
various ethers, being a colorless liquid of burning acrid taste and 
odor very irritating to the lungs, with a specific gravity of 0.818. 
The last is made usually from potatoes. None of these really are 
solvents of rubber, but are frequently and largely used in var- 
nishes. India-rubber, when treated with large quantities of al- 
cohol, is deposited in a spongy form, the foreign ingredients in 
the gum going into solution. Treated in this way it can be made 
an exceedingly white mass. It is also used in treating many of 
the pseudo guttas to dissolve out the brittle resinous matters. It 
has also been claimed that the washing of raw rubber with alcohol 
dissolves resinous ingredients which are better absent, and that 
the rubber as a result lasts longer. Rectified spirit is what is 
generally known, or rather, used, in connection with India-rub- 
ber. It is used by the gatherers to coagulate the sap of the Ba- 
lata, and is used also in the production of resinolines (which 
see). One of the early uses was to mix with it various solvents — 
for instance, with spirits of turpentine, coal oil, bisulphide of car- 
bon, ether, chloroform, etc. When ill-smelling solvents were used, 
it was also often incorporated to neutralize the odor. In the Azo 
process for reclaiming rubber, 20 parts of alcohol to i part of 
bisulphide of carbon are used for softening and reclaiming rub- 
ber. Dental and other gums are exposed to the sunlight in Alco- 



i84 SOLVENTS FOR RUBBER. 

hoi to increase the brilliancy of the colors and to make the shades 
lighter. Alcohol is also used to soften vulcanized rubber when 
a surface color is to be added. Alcohol, in connection with nitric 
acid, spirits of turpentine, and aniline, was used by Kelly for sur- 
face work on India-rubber. 

Anthracine. — A trade name for napthaline (which see.) 
Benzol or Benzole is a volatile oil obtained in the distilla- 
tion of coal tar, which must not be confused with coal tar naph- 
tha. Its specific gravity is 0.899 ^^ 32° F., and 0.878 at 68° F. 
It is slightly soluble in water, and freely soluble in alcohol and 
ether, and in bisulphide of carbon. It is sold according to its per- 
centage of pure benzol. It has great solvent properties. Benzol 
is used largely as a solvent for rubber in manufacturing bicycle 
cements, and also for dissolving rubber, and for the cold vulcani- 
zation of thin rubber fabrics containing chloride of sulphur, in 
which Benzol is much superior to carbon bisulphide; and at pre- 
sent it is much cheaper, both on account of less loss in handling, 
and also, of its much lower price per gallon. This refers more 
particularly to the high grades of Benzol, like ioo per cent, or 
C. P. ; the 160° Benzol is mostly used where a solvent is required 
that must not evaporate too rapidly. It is said that if Gutta-per- 
cha is put in 20 times its weight of boiling Benzol, to which i-ioth 
of plaster is added, and the mixture agitated from time to time, 
a perfectly clear solution is decanted. This is then mixed with 
twice its volume of 90 per cent, alcohol and the Gutta-percha pre- 
cipitated a pure white. (See Naphtha.) 

Bisulphide of Carbon is a transparent liquid, the specific 
gravity of which is 1.27. It is exceedingly volatile, evaporating at 
ordinary temperature. When properly made its smell is some- 
what similar to chloroform. The bad smell found in some is due 
to sulphureted hydrogen, and the presence of foreign matters 
from which it can be thoroughly freed by purification. It is high- 
ly inflammable, though not explosive, and has great affinity for 
sulphur, 100 parts dissolving 37 parts of sulphur, cold ; and at 100° 
F. the same quantity will dissolve 94.5 parts. Bisulphide of Car- 
bon mixes with every known substance capable of vulcanizing 
rubber. It also assimilates rapidly with all fatty oils, and dis- 
solves all the resins, with the exception of shellac. It does not 



BISULPHIDE OF CARBON— CAMPHOR. 185 

dissolve vulcanized rubber, however. Where it is used in rubber 
factories care is taken, as a rule, to remove the fumes, as they are 
injurious to the workmen. Some very serious cases of chronic 
poisoning have occurred through the use of this solvent, the 
symptoms being numbness, partial paralysis, and, in some cases, 
temporary insanity. The use of Bisulphide of Carbon in rubber 
factories is very carefully watched, therefore, by the authorities 
in Europe, proper means for ventilation and carrying off the 
fumes being insisted upon, and minors being excluded from rooms 
where it is used. It is one of the best and most common solvents 
for India-rubber, very largely used in the Parkes cold curing and 
similar processes, and in cements. 

Bisulphide of Carbon Substitute is a liquid produced by 
Dr. Carl Otto Weber, which is said to be a perfect substitute for 
bisulphide of carbon. It had these advantages: less chloride of 
sulphur was needed, the smell of the vulcanized product was 
sweeter, the vulcanizing solution penetrated deeper into the rub- 
ber, the risk of burning the rubber and the uneven vulcanization 
was also done away with. It is also said that this substitute is 
not injurious to the health. It is manufactured in England. 

Borax is sometimes used as a solvent for rubber. (See 
Acids and Alkalies.) 

Camphine is a name applied to one of the varieties of spirits 
of turpentine which was once largely used as a burning fluid. It 
is very volatile, and the vapor may exist in the air in explosive 
quantities. Camphine was formerly used to a certain extent as a 
solvent for India-rubber. Under Newton's method of recovering 
rubber, the waste was placed in a closed vessel, covered with 
Camphine, and heated to 158° F. or fourteen days. The solvent 
was then distilled off, and the tough mass remaining was capable 
of utilization, and was somewhat similar to unvulcanized rubber. 
It was also used in the boot heel cements in the old-fashioned 
method of attaching them to rubber boots, and also in general 
shoe cements. Camphine was also used in putting vulcanized 
waste, finely powdered, into a solution in connection with ether 
and alcohol, in a simple but somewhat expensive process of re- 
covery. 

Camphor has been used as a solvent for utilizing the 



i86 SOLVENTS FOR RUBBER. 

waste of vulcanized rubber and of hard rubber, the waste being 
first treated with any ordinary solvent and then placed in a still 
with a certain amount of camphor, when the India-rubber is dis- 
solved and the solvent passed out and distilled over again. Granu- 
lated Camphor, over which had been passed sulphurous acid gas 
until it was reduced to a liquid, was used also as a solvent for 
India-rubber, by Alexander Parkes. (See Gums, etc.) 

Caoutchoucine, also spelled Caoutchine, is a crude oil of 
India-rubber, made by its dry distillation, and smelling much like 
naphtha. It is an excellent solvent for India-rubber, but of course 
is too expensive for ordinary use. India-rubber immersed in it 
swells exceedingly, and a considerable quantity of it is dissolved 
during the boiling. It must be kept in hermetically sealed vessels, 
as it has a great affinity for oxygen, which it absorbs energeti- 
cally. In preparing it, the India-rubber is treated in a retort at 
a heat exceeding 400° F. Caoutchoucine dissolves in ether or 
alcohol, and, absorbing oxygen freely, forms a resinous body as 
a result. 

Chloride of Carbon. — This is obtained by the distilling 
of bisulphide of carbon into a vessel containing penta-chloride 
of antimony, the product being rectified by distilling with lime. 
According to Simpson, this makes a good solvent for India-rubber 
and in a measure vulcanizes it. Newton also used a chloride of 
carbon in dissolving both India-rubber and Gutta-percha, while 
Crump used tetra-chloride of carbon. 

Chloroform is prepared generally by distilling together a 
mixture of spirit — that is, wood alcohol — with bleaching powder, 
slaked lime, and water. Its density is from 1.496 to 1.498. It 
is one of the best rubber solvents known. It is costly, however, 
and has a bad effect upon workmen. Lascelles-Scott mentions 
what he calls the A. C. E. mixture which is composed of alcohol 
15 parts, chloroform 38 parts, and ether 47 parts, which yields 
a powerful solvent for India-rubber or Gutta-percha. Chloro- 
form dissolves not only India-rubber, but fats, resins, sulphur, 
alkaloids, and many other organic compounds. It should be re- 
membered that a small percentage of chloroform in the air, even 
as little as 5 per cent., is dangerous to the workmen. Chloroform 
is used as the solvent for India-rubber which is treated with the 



CHLOROFORM— ETHER. 187 

ammoniac gas process for bleaching. Is also used alone, and in 
connection with naphtha for rubber cements, which are intended 
to adhere to glass. In the bleaching of Gutta-percha, it is also 
used as a solvent. One of the first uses of Chloroform in con- 
nection with India-rubber is to be jioted under a patent granted 
to Charles F. Durant, who announced the discovery of a solvent 
known as "perchloride of formyle, otherwise known as chloro- 
form.'^ 

Creosote Oils, in connection with ordinary solvents for In- 
dia-rubber, are said to produce a cheap and effective solvent. 
Indeed, John Bagnol, manufacturer for Charles Macintosh & Co., 
patented their use as applied to India-rubber. (See Creosote.) 

DiPPEL^s Oil (or Bone Naphtha). — A thick, viscid oil of 
brown color and very disagreeable odor, which on distillation 
may be obtained limpid and colorless. It is prepared by the de- 
structive distillation of bones, leaving boneblack as a residuum. 
It was one of the early solvents used for India-rubber. 

Ether. — This was one of the early solvents used in connec- 
tion with India-rubber. It is sometimes called sulphuric ether, 
but erroneously. It is prepared usually by distilling a mixture of 
alcohol and sulphuric acid, washing the distillate, and rectifying 
the product with quick lime or something of that kind. It is a 
colorless, very mobile liquid, with a not unpleasant smell, burn- 
ing taste, and very volatile. Its specific gravity is 0.736. It is 
soluble in water i to 12. Commercial Ether boils at 96° F., and 
yields a dense vapor.. It is very inflammable, and, when mixed 
with air or oxygen, gives rise to a dangerous explosive mixture. 
It is one of the best solvents known for oils and fats, and is also 
an excellent solvent for sulphur. For use in rubber work Ether 
should be free from water, but not absolutely pure, necessarily. 
It is little used to-day in rubber mills, except in some lines of very 
fine work. It has the advantage of being absolutely free from 
the smells that many solvents have. A little is sometimes added 
to ordinary rubber solutions to make a complete solution of India- 
rubber in naphtha. There are also certain processes, expensive 
ones to be sure, for treating perished rubber with Ether vapor to 
recover it. Ether was used to remove sulphur from vulcanized 
India-rubber waste in Newton's camphine process. 



i88 SOLVENTS FOR RUBBER. 

Gasoline. — See Naphtha. 

Heptane. — One of the four isomeric hydrocarbons of the 
paraffine series, which occurs as a colorless liquid and is derived 
from heavy cannel coal oil, petroleum, etc. Its specific gravity 
is 0.712. It is soluble in alcohol and in ether, and is used with 
paraffine wax and India-rubber in water-repellent compounds. 

IsopRENE. — A body which is found in oil of caoutchouc. It 
boils at 98.6° F., and possesses the property of absorbing quanti- 
ties of oxygen when exposed to the air, in consequence of which 
it forms itself into an elastic spongy mass. This same volatile 
compound is obtained by the action of moderate heat on oil of 
turpentine. William A. Tilden, D. Sc, F. R. S., had some Iso- 
prene from turpentine placed in a bottle, his first result being a 
limpid, colorless liquid. After a time, this changed in appearance, 
looking like a dense syrup, on which floated several hard elastic 
masses. On examination, they turned out to be practically 
India-rubber. This rubber united with sulphur in the same 
way as ordinary rubber, forming a tough, elastic compound. It 
was also soluble in benzine, etc. Dr. Weber, before the Society 
of Chemical Industry, reported on Tilden's discovery that Iso- 
prene is so expensive it cannot be converted into rubber without 
loss, and therefore the synthetical manufacture of India-rubber, 
even if possible, was not probable at the present time. 

LiGROiN. — See Naphtha. 

Methane. — Professor Lascelles-Scott describes the manu- 
facture of what he calls Methane solvents, which are really ben- 
zines or benzols through which marsh gas has been passed. He 
claims that a benzine containing from 2 to 3 per cent, of Methane. 
obtained in this way, yields a better and more mobile solution than 
the ordinary solvent naphtha, and the solution when spread dries 
off better, besides giving a more finished surface. 

Methylated Alcohol is also called methylated spirits, and 
wood spirits. It is obtained by the distillation of wood, and in 
the course of beet sugar manufacture. It is a colorless mo- 
bile liquid, of a vinous smell, similar to common alcohol. Its 
specific gravity is 0.814. It always contains acetone. Although 
not used in rubber solutions, it is a very common solvent for cel- 
lulose products which, through their increasing importance, are 



NAPTHAS. 189 

attracting the interested attention of the rubber trade. Used un- 
der Vaughn's patent, to coagulate Balata. 
\( Naphthas. — The term Naphtha was originally applied to a 

variety of pungent, volatile, inflammable liquids that belonged 
chiefly to a class of ethers; then it took in oils of natural origin, 
such as rock oil, petroleum oil, etc; at a later date, a light oil of 
coal tar, which should properly be designated benzol, was in- 
cluded under the name of Naphtha; while recently it has been 
extended so that it covers most of the inflammable liquids dis- 
tilled dry from organic substances. It is applied in the United 
States to a series of hydrocarbons that are obtained from petro- 
leum, whose boiling points vary with the densities, from 65 to 
300° F. The Naphthas of commerce are bog-head naphtha, ob- 
tained from bog-head coal; bone naphtha, or DippeFs animal oil; 
coal naphtha, obtained from the distillation of coal tar; wood 
naphtha, or methyl alcohol obtained during the dry distillation 
of wood. Of these, coal tar naphtha and petroleum naphtha are 
most useful to rubber manufacturers. The former of these was 
used largely as' a rubber solvent, but to-day it is almost wholly 
replaced by petroleum naphtha. The Naphtha which is derived 
from petroleum comes between gasoline, which is lighter, and 
benzine, which is heavier. Benzene is contained in the naphtha 
produced by the destructive distillation of coal, while benzine is a 
petroleum product. Benzine is really the first product that arises 
from the process of refining crude oil, and bears the same relation 
to naphtha that the distillate does to refined oil, thus showing 
that benzine is simply a crude Naphtha. What is known as gaso- 
line has a proof rate of 86° F., and boils at 90° to 100° F. Warm 
currents of air volatilize this type of Naphtha very rapidly, and 
its vapor unites with the atmosphere in explosive proportions. 

Coal-tar Naphtha was one of the first solvents used in rub- 
ber work. Macintosh, as far back as 1823, prepared it himself 
for dissolving India-rubber for proofing. There is obtained from 
crude Coal-tar Naphtha what is known as "once run" Naphtha 
and "last runnings.'' The once run Naptha is the starting point 
from which are derived the various grades of benzols, solvent 
Naphthas, etc., by fractional distillation. The specific gravity of 
solvent Naphtha should not exceed 0.875. Its composition is a 



I90 SOLVENTS FOR RUBBER. 

very complex affair, including xylols, cumols, homologous of ben- 
zol, together with some paraffine, and sometimes a little naphtha- 
line. This last-named substance, by the way, is often objection- 
able, as it acts upon some rubbers like animal oil. Naphtha de- 
rives its vegetable solvent power largely from the xylol present in 
it. This is to-day removed and sold by itself as a solvent, though 
the residual Naphtha is simply robbed of that much virtue. 

Speaking of Naphthas, Lascelles-Scott, after exhaustive ex- 
periments, thus describes three used in England in rubber fac- 
tories. Petroleum Naphtha in its solvent action on rubber showed 
slight action in the cold or under gentle heat. Viscid masses and 
semi-solutions were formed, but these solutions did not dry well. 
The same Naphtha had almost no solvent action on pitch. Shale 
Naphtha was useful only in dissolving Madagascar rubbers, and 
had no action on pitch, while coal-tar Naphtha caused almost any 
rubber to swell quickly and, after gentle heat, to effect a good 
solution. It also readily dissolved pitch, forming a deep brown 
solution. 

The problem that confronts rubber manufacturers as a rule 
is the solution of gums that are more or less heavily compounded, 
which is an easier problem than the putting into solution of crude 
rubber that perhaps has not been broken down in any way. At 
the same time it is customary in many cases to apply a little heat 
during the mixing. The following table relates to petroleum 
Naphthas. The C Naphtha has not only the greatest solvent 
power, but it is easier to evaporate after it has dissolved the rub- 
ber compound. B and A require a certain amount of heat to 
vaporize them. 

Specific Degrees Boiling 

Products. Gravity. Beaume. Points. 

Rhigolene 0.625 •• 65° F. 

Gasolene 0.665 85 120'' F. 

C. Naphtha 0.706 70 180° F. 

B. Naphtha 0.724 67 220° F. 

A. Naphtha 0.742 65 300° F. 

Naphtha is more largely used in the proofing business than 
any other. It is, however, a general solvent for cements, and 
quantities of it are used in almost all lines of rubber work where 
there is any making up to be done of separate pieces after calen- 
dering. It is therefore necessary that a good grade be used, when 



NAPTHAS—OIL OF TURPENTINE. 191 

one considers the danger that may come from fires caused by the 
explosion or easy ignition of low grade solvents. Odorless Naph- 
thas are those from which naphthalene, a solid white body, has 
been removed, as it is the presence of this body that causes the 
strong smell. Naphtha treated by sulphuric acid is deodorized, 
acquiring a rather pleasant odor as a consequence. It is often 
mixed with other solvents — for example, with oil of turpentine — 
and is found thus to have a better effect on the rubber. 

Naphthaline (called also Anthracine). — Commercially 
obtained from coal tar, being among the third and fourth pro- 
ducts of the distillation of that body. Naphthaline is usually sold 
in rolls made by melting the large silvery plates or scales in which 
it crystalizes and running the melted compound into molds. Its 
specific gravity is 1.15. It is insoluble in water and petroleum 
naphtha, but the liquids derived from coal tar dissolve it easily. 
Naphthaline is sparingly soluble in alcohol and ether, but readily 
in benzol. It is used in insulating paints, as when it evaporates 
it leaves a very solid film that is said to be absolutely free from 
porosity. 

NiTRo Benzol, — A compound obtained by boiling benzol 
with nitric acid. It is a brown, heavy, oily looking liquid, having 
a specific gravity of i .2, a burning sweet taste, and a smell resem- 
bling that of oil of bitter almonds. It is used in the analysis of 
vulcanized India-rubber to dissolve the substitute that may be 
incorporated in it. It is produced by the action of nitric acid on 
benzene, also called nitro-benzene. Used by Parkes in the manu- 
facture of Parkensine. ( See Acids and Alkalies ; also Naphtha. ) 

Oil of Turpentine (crude) is what is known as an oleo 
resin, and is of about the consistency of fresh honey. There are 
more than a dozen varieties on the market, the more common be- 
ing Bordeaux, Venice, Canadian, and American. A fair quality 
of turpentine oil should begin to boil at 160° F. The distillation 
of turpentine in water produces ordinary resin. Oil of Turpen- 
tine is used in certain waterproof cements, in connection with 
both Gutta-percha and India-rubber. Where oil of turpentine 
is necessary for rubber work, it is well to have it free from the 
considerable percentage of water which it invariably contains. 
This is done by a treatment with sulphuric acid, or by rectifying 



192 SOLVENTS FOR RUBBER. 

it over burnt lime. Turpentine, particularly that known as Venice 
Turpentine, is often used in connection with linseed oil and sul- 
phur in the production of rubber substitutes. Professor Tilden 
showed, some years ago, that what appeared to be pure India- 
rubber could be obtained from turpentine; indeed, he announced 
that he had produced it on a small scale. The same thing was 
also observed by Bouchardt. Venice Turpentine is obtained from 
Switzerland, where it is procured from the Larix Euro pea, or 
larch. The genuine Venice Turpentine is of the consistency of 
honey, cloudy, yellowish, or slightly greenish. It is entirely solu- 
ble in alcohol. The commercial Venice Turpentine is a factious 
substance, usually quite brown, and is prepared by dissolving 
rosin in oil of turpentine. Venice Turpentine is largely used in 
cements. Bordeaux Turpentine is the ordinary turpentine of com- 
merce, getting its name from the port in France whence it is ex- 
ported. (See Spirits of Turpentine.) 

Pentane. — A hydrocarbon of the paraffine or methane se- 
ries. A colorless, volatile liquid which occurs in petroleum. Pen- 
tane is used with parafhne wax and India-rubber in water-repel- 
lent compounds. 

Petroleum. — A mixture of several hydrocarbons which, in 
fluid form, issue from the ground in many parts of the world; 
also known as rock oil. It varies in consistency from a thin, 
fight, colorless fluid with a specific gravity of about 0.750, to a 
substance as thick as butter, and almost as heavy as water. All 
kinds, however, have about the same constitution, consisting of 
carbon and hydrogen compounds only, and containing no oxygen. 
Asphalt and bitumen are closely allied to petroleum. This oil is 
often used for restoring rubber that is oxidized somewhat, by im- 
mersion, and then hanging for a couple of days in a warm atmos- 
phere. Petroleum is very rarely used in rubber manufacture, for 
although a good solvent, it weakens the goods exceedingly. Crude 
petroleum, however, is a valuable adjunct to the reclaiming of 
rubber, where, in the form of a cheap residuum, it assists in de- 
vulcanization and in sheeting. (See Naphtha.) 

Thion. — A substitute for bisulphide of carbon, manufac- 
tured in England, which is said to mix excellently with chloride 
of sulphur and is non-poisonous. 



TOLUENE— SPIRITS OF TURPENTINE. 193 

Toluene. — That oil which is distilled from coal tar at a tem- 
perature of 230° to 234° F., also called methyl benzine and Tol- 
uol. It resembles benzene in outward appearance. Two-thirds 
of the commercial 50 per cent, benzol is made up of Toluene, and 
this it is that makes it a far better solvent for rubber than ben- 
zine itself, as it dissolves the rubber in five-sixths of the time. The 
solutions are more mobile; it has a higher boiling point; and, 
given a quantity of the solvent, will reduce more gum. It does 
not chill in cold weather, but keeps on macerating. It leaves a 
more solid deposit than does benzine, and does not induce head- 
ache or sickness among the workmen. [Lasceiies-Scott.] 

Resin Oil. — This is obtained by subjecting rosin to dry dis- 
tillation, the specific gravity of the resultant oil ranging from 
0.96 to 0.99. It is rarely used as a solvent for rubber, in the ordi- 
nary meaning of the term. As a matter of fact, it is not a good 
solvent for crude rubber. For compounded rubbers, however, 
it also works well and is often used, particularly in connection 
with pseudo guttas. In certain insulating experiments, where a 
thin sheet of Gutta-percha covered the conductor, and the outer 
Gutta-percha tube was full of resin oil, it gave, according to Pro- 
fessor D. E. Hughes, F. R. S., a higher insulation test than Gutta- 
percha alone. Professor Hughes used resin oil quite thick and 
viscid, and added resin and a solid residuum obtained from the 
distillation of palm oil. Resin oil in rubber compounding, how- 
ever, softens the compound in a marked degree. (See Oils.) 

Rhigolene. — See Naphtha. 

Spirits of Turpentine is really oil of turpentine, and it has 
a specific gravity of 0.864. It is colorless, transparent, of a strong 
odor, and a bitter taste. It is insoluble in water, on which it floats, 
but readily soluble in alcohol, ether, and the fixed and essential 
oils. It is an excellent solvent for sulphur, resin, and India-rub- 
ber. Spirits of turpentine, with wood spirit alcohol, aniline, and 
nitric acid is used in surface work on vulcanized India-rubber. 
The earliest records of India-rubber speak of this oil as a solvent 
for it ; indeed, the whole secret of rubber compounding for a num- 
ber of years, even when the great Roxbury Rubber Co., of Bos- 
ton, was running, was the solution of India-rubber in it. It is 
used in solutions that are expected to be sticky, and to dry slowly. 



194 SOLVENTS FOR RUBBER. 

VuLCOLEiNE is a liquid of English origin, and is put upon 
the market at about the same price as carbon bisulphide, and used 
for a solvent for India-rubber. It leaves on evaporation a per- 
fectly tough and elastic film, quite unlike that left by coal tar 
naphtha, or the usual solvents. It mixes instantly with chloride 
of sulphur, and is intended to replace bisulphide of carbon in the 
cold curing process. It has no bad smell, nor is it unhealthful. 

Wood Spirit (also known as Pyroxylic acid). — This is made 
from the destructive distillation of wood. Wood Spirit resembles 
alcohol and its affinities, forming an ether and a series of com- 
pounds exactly corresponding to that of spirits of wine. Wood 
Spirit, when pure, is a thin, colorless liquid, with a peculiar odor 
and a hot disagreeable taste. It boils at 152° F., and its density is 
.798 at 60°. It mixes freely with water, and, like alcohol, dissolves 
resins and volatile oils, and is used as a cheap substitute for that 
purpose. Wood Spirit, also known as methylic alcohol, is not me- 
thylated spirit. It is not a solvent of rubber, but is used in many 
compounds that are intended as substitutes for vulcanized rubber. 
It is also used in dyeing India-rubber in connection with nitric 
acid, alcohol, and aniline. 

Xylol. — A colorless, somewhat aromatic, inflammable, oily 
liquid found in coal tar and wood tar ; also called Xylene. It is 
really the solvent principle found in mineral naphthas. (See 
Naphtha.) 



CHAPTER XII. 

MISCELLANEOUS PROCESSES AND COMPOUNDS FOR USE IN THE RUBBER 

FACTORY. 

Many interesting formulas are given for the dyeing and sur- 
face coloring of rubber, although the processes are not such as 
will generally be used. A suggestion that comes from France is 
the dipping of rubber for an instant in a bath of nitric acid, then 
washing in water. For coloring, the rubber is dipped in an alco- 
holic solution of fuchsine. The experimenter should appreciate 
fully, however, the effect that nitric acid produces on rubber, and 
govern himself accordingly. 

Alexander Parkes, who produced some exceedingly valuable 
processes for the treatment of rubber, gives the following for- 
mulas for dyeing India-rubber: 

Black. — Boil from 15 to 30 minutes in a liquid prepared as 
follows : Sulphate copper, i pound ; water, i gallon ; caustic am- 
monia or muriate of ammonia, i pound. Or: Sulphate of bisul- 
phate potash, i pound ; sulphate copper, 12 pounds ; water, i gal- 
lon. 

Green. — Muriate ammonia, 2 pounds; sulphate copper, i 
pound; caustic lime, 4 pounds; water, i gallon. Boil the rubber 
as before, 15 to 30 minutes. 

Purple. — Sulphate or bisulphate of potash, i pound ; sulphate 
of copper, ^ pound ; sulphate of indigo, ^ pound. Boil the rubber, 
15 to 30 minutes. 

Hoffer gives almost the same ingredients for producing these 
colors, adding the information that the articles are dyed by being 
boiled in these fluids from 15 to 30 minutes, the thicker the arti- 
cle the longer the boiling. This is done before the goods are vul- 
canized. 

Hard rubber may be decorated by means of pigments mixed 
with shellac and applied to the given surface with a brush. The 
surface then is to be pressed with some force against a hot plate 
of metal, whereby the colors are made to appear as though inte- 
gral with the rubber. 

Wood coated a sheet of vulcanizable rubber with chloride of 

195 



196 MISCELLANEOUS PROCESSES. 

silver, the idea being to use it in dental plates. Various processes 
have also been brought out for the surface treatment of rubber 
with gold leaf, bronzes, etc., usually applied in the form of pow- 
ders, in the manner in which flock is applied. Truman also pa- 
tented a process for electro-gilding rubber dental plates after 
they were finished. Goodyear dusted unvulcanized rubber sur- 
faces with plumbago or powdered metal, to make them conduc- 
tive, pressed the dust in, and then electroplated it. 

The embossing of India-rubber surfaces has been practised 
almost since the invention of the "triple compound."" It is really 
nothing more than a light surface molding. This is done some- 
times by embossing rolls, the rubber being cured after the impres- 
sion is taken, and sometimes by being vulcanized on the impres- 
sion plate. 

Bourbridge patented a process for embossing rubber by roll- 
ing it tightly on a drum with embossed paper or bookbinders' 
cloth, and semi-curing it in that form, preferably by boiling at a 
temperature from 212° to 220° F. This boiling operation was 
not really vulcanization, but simply a means of setting the rubber 
which was afterward made up into goods and cured. 

In producing sheets of India-rubber for the manufacture of 
tobacco pouches, balls, balloons, etc., by this process, the sheet is 
calendered on sized cloth, partially vulcanized, printed, coated 
with transparent India-rubber, the goods made up, and the vul- 
canizing process completed. 

A great many beautiful colors are added to India-rubber sur- 
faces by coating the sheet with a thin adhesive solution, dusting 
it over with colored flock, and then vulcanizing. By this process 
any color can be given to rubber surfaces which have a cloth-like 
appearance. 

Kelley produced a bronzed appearance on rubber coated fab- 
rics by means of a roller partly immersed in a trough holding the 
dye, curing either by dry heat, or by chloride of sulphur. His 
solution consisted of 2 ounces alcohol spirits, i ounce wood naph- 
tha, 10 drops nitric acid, i ounce spirits of turpentine, with suffi- 
cient aniline dye to make the desired color, 4 ounces liquid dye- 
ing, 3 pounds rubber composition. He also impregnated farina 
with aniline solutions, dried it, and mixed it in the compound. 



COLORED DESIGNS FOR FABRICS. 197 

In certain dyeing processes lakes are necessary. What is 
known as caoutchouc lake is made by steeping i ounce of Para 
rubber in a quart of light camphor oil, exposed to the sunlight for 
several days. This is said to be excellent for binding colors. 

Matthew's process for producing colored designs for proofed 
fabrics is to first coat the fabric in the ordinary manner with pure 
or colored India-rubber. When the design is to be printed on a 
black or dark ground, the last coating is mixed with starch or 
some powder that will render it non-adhesive, and to an extent 
absorptive. The fabric is then partially vulcanized, when the de- 
signs are printed on the desired surface, just as oil-cloth or lino- 
leum is printed. The vulcanization is finished preferably by using 
chloride of sulphur. 

Colors suitable for admixture with rubber should answer the 
following requirements: They must be unaffected by water, by- 
acids, by alkalies, and by chloride of sulphur. Further than this, 
they must not be affected by sulphur at temperatures ranging from 
200° to 300° F. The colors must not be soluble in or affected by 
naphtha or other solvents used in rubber work. They must not 
be affected by heat up to 300° F. According to Frankenburg, 
his invention of aniline lakes answers all these requirements. His 
description is as follows: 

(A) Lakes prepared from acid aniline colors. — 'Thavefound 
that by converting any of the acids or sulphonated aniline colors 
into compound lakes, such as barium-alumina, calcium-alumina, 
barium-chromium, or calcium-chromium lakes, colors are obtain- 
ed answering all the above requirements, and therefore eminently 
suitable for the dyeing of India-rubber, waterproof, and other 
articles. The aniline dyes best suited for the production of these 
lakes are those known as azo or dis-azo colors. From colors of 
this description I prepare lakes in the following manner: 50 
pounds of orange II., or any other suitable azo or dis-azo color, 
and 112 pounds of soda crystals are dissolved in 100 gallons of 
water at 170° F. This solution is then precipitated with a solu- 
tion of 150 pounds of barium chloride. The precipitate is kept 
boiling for half an hour. It is then left to stand, and washed seve- 
ral times with fresh water. Eventually a solution of 40 pounds 
of alumina sulphate is added very gradually, when a bright, fast, 



198 MISCELLANEOUS PROCESSES. 

and flocculent lake is obtained, which, after filtration, drying, and 
pulverizing, is ready for incorporation with the India-rubber 
dough. It is evident that a great many variations of the process 
may be devised, but in every case the important point is the con- 
version of the aniline dye into one of the above-mentioned com- 
pound lakes. As regards the proportions given above, they are, 
of course, subject to such variations as are in accprdance with the 
molecular weights and the commercial purity of the materials 
used, as well as with the particular properties and qualities to be 
imparted to the lakes for the purpose they are intended to serve. 
Using in this manner the numerous azo and dis-azo dyes a very 
great variety of lakes may be produced, comprising all conceivable 
shades, and all suitable for the dyeing of India-rubber articles of 
every description. The lakes prepared from the acid oxy-ketone 
dyes and most of the natural dyes are very little suitable for this 
purpose, owing to their indifferent and dull shades." 

(B) Lakes prepared from basic coloring matters. — "A large 
number of lakes derived from this class of dyes are also suited 
for the dyeing of India-rubber articles, although many of them 
are lacking in fastness to light acids and alkalies. To produce 
a perfect compound lake from these dyes tannic acid and anti- 
mony, along with aluminum and barium, are used for the complete 
fixation and precipitation of these lakes. The following propor- 
tions give good results: Soda carbonate, 128 pounds; barium 
chloride, no pounds; thioflavine, 25 pounds; tannic acid, 20 
pounds, acetate of soda, 20 pounds; sulphate of alumina, 100 
pounds. These colors can be made faster by adding to them a 
small quantity of antimony potassio-tartrate. The proportions of 
tannic acid, sodium acetate, and tartar emetic used in this process 
vary considerably w4th the different basic colors, such variations 
being due to the difference in the atomic weights and commer- 
cial purity of the basic dyes." 

Hebblewaite and Holts's process for producing designs on 
gossamer cloth calls for the spreading over the rubber surface of 
farina or other powder, then running the fabric through embos- 
sed rollers and producing patterns thereon. 

Mosley^s ornamented fabric was a gossamer cloth covered 
with farina, the surface being printed much as calico is, and then 



THE CRAVENETTE PROCESS. 199 

vulcanized with chloride of sulphur. The colors were mixed with 
suitable solvents and a certain amount of paraffine or India-rub- 
ber added. A part of this invention was also the use of an en- 
graved roller, which revolved in the vulcanizing solution, and 
came in contact with the surface of the rubber, only at its raised 
portion. Directly after passing over the roller, if the surface of 
the rubber were dusted with farina, it would adhere to the por- 
tions that had come in contact with the roller, and not to the rest, 
thus producing a design on the fabric. The whole of the coating 
was afterwards cured by vapor. 

SHOWER-PROOF PROCESSES. 

The Cravenette and other processes for rendering textile 
fabrics waterproof or water-repellent have attracted so much at- 
tention in the rubber trade that space will be given here to a de- 
scription of the Wiley patent, which is used at the Cravenette 
Works, Bradford, England. To begin, the waterproofing com- 
pound is applied in a solid or hard state by the action of friction 
and heating. In other words, there are no solvents used, nor is 
it a calendering process. The advantage of this is a lessening in 
the cost of applying waterproofing solutions and a further valua- 
ble result is that the dyes on various fabrics are in no way dis- 
turbed, and no unpleasant odor is developed or imparted to the 
cloth. The substances chosen are those which have a low melt- 
ing point, so that the fabrics are not damaged by heat. They are 
preferably ozocerite, stearine, spermaceti, paraffine wax, beeswax, 
or Japanese wax. These are sometimes used singly, and sometimes 
in combination, considerable judgment being necessary in selecting 
those which have an affinity for or are readily absorbed by the 
fibers of particular fabrics, influenced also by the nature and 
color of the fabric. In some cases India-rubber, Gutta-percha, 
maltha, asphaltum, resin, and artificial gums are found valuable 
in small proportions, and in conjunction with the substances al- 
ready mentioned. 

In order to apply the waterproofing substance, it is formed 
into slabs. The fabric is carried on a reel supported in bearings 
between suitable frames, at the opposite end of which is a hollow 
cylinder mounted upon carrying rollers and supported laterally 



200 MISCELLANEOUS PROCESSES. 

by side rollers. This cylinder is filled with water. The slab of 
the compound, wider than the fabric to be coated, is fixed in a 
holder above the cylinder. This holder is so arranged that the 
weight presses the slab against the cylinder. The fabric is then 
drawn from the reel over and under tension bars, under a support- 
ing roller, between it and the rubber cylinder, and around the 
cylinder and under the slab, then over the guide roller and into a 
drying machine. The friction of the cloth wears the slab awaj 
and uniformly deposits it upon the cloth, while in the drying ma- 
chine, the heat melts the waterproofing compound, and it is ab- 
sorbed by the fibers which are thereby rendered waterproof or 
water-repellent. 

Other formulas for shower-proofing and waterproofing are 
of interest in this connection and a few are given: 

The first is a German waterproofing compound: Alum, 10 
pounds; sugar of lead, 10 pounds. Dissolve in hot water and 
allow the precipitate to settle. Dilute the clear liquid with 120 
gallons water and add 2 pounds isinglass in solution. The goods 
are steeped in this solution 8 or 10 hours. 

An American shower-proof compound: Liquid silicate of 
soda or liquor of flint, i gallon ; white oxide of zinc, i pound. If 
the fabric is to be colored, add coloring matters. The mixture 
may be applied to fabrics hot or cold, by means of a brush or by 
immersion of the fabrics, which are afterwards to be run between 
rollers. 

Another American compound : Dissolve separately, 1^ pounds 
alum (in hot water), 10 ounces acetate of lead (in hot water), 
and 1 1 pounds carbonate of magnesia (in hot water). They 
should aggregate about 31 quarts. Add the acetate of lead to the 
alum solution, and then the carbonate of magnesia; after which 
10 quarts liquid as above and i tablespoon white gum arabic. Stir 
^ hour ; let stand 24 hours, skimming now and then ; in 48 hours 
the first mixture will be ready. Lay the fabric in a vessel and 
pour liquid over it, beating the fabric well and removing it withi« 
an hour. 

A third American shower-proof compound : 

A. Carbonate of soda 16 parts. 

Lime 8 parts. 

Water. 32 parts. 



WATERPROOFING COMPOUNDS. 201 

Boil 30 minutes, let settle and pour off the clear lye. 

B. Glue or gelatine 3 parts. 

Linseed oil 3 parts. 

Add after soaking glue in cold water 12 hours. 

C. Tallow (or other animal fat) 16 parts. 

Rosin 8 parts. 

Melt together. 

To (A) boiling hot add hot (C), then pour in (B) and stir hot until well 

mixed. 

D. Sulphate of alumina i pound. 

Acetete of lead i^ pound. 

Boiling water 8 gallons. 

Let settle and draw off clear liquor for use. To i gallon water add X 
ounce of first product for bath for cotton goods. Add 3^ ounce for silk 
or wool. Immerse 24 hours or more, then six hours or more in second 
compound (D). 

Proofing compound: 

Mixture i. — Dissolve in water, 50 parts alum; also dissolve 
in water, 35 parts sugar of lead ; mix. 

Mixture 2. — Combine 17 parts paraffine and 35 parts ben- 
zine; drop into this 17 parts Caoutchouc. Stir until well dis- 
solved. 

Mixture 3. — To the clear decanted liquor from the above 
mixtures, add 8 parts alcohol and 4 parts eau de cologne (or oil 
of lemon.) 

An English compound for waterproofing textile fabrics: 
Sugar soap, i pound; water, 16 gallons. Soak articles in them 
for 6 hours ; drain, but do not wring them ; and place them in the 
following solution : 

Alum, I pound ; water, 16 gallons ; soak again 6 hours, take 
out and dry without wringing. 

Another English compound for waterproofing textile fabrics : 
Concentrated size, 8 pounds; aluminum sulphate, 5 pounds; ba- 
rium chloride, 6 pounds; water, 16 gallons. After coating, var- 
nish with the f olio wing: Melt together 22 pounds colophony, 
4 3"5 pounds crystalized soda, and 1 1 pounds water. Then add : 
Ammonical fluid, 5^ pounds; and water, 55 pounds; or: Borax, 
6 pounds ; shellac, 6 pounds ; and water, 40 pounds. 

A German compound for waterproofing woolens: Dissolve 
100 pounds alum in moderate quantity of boiling water ; soak 100 
pounds glue till it has taken up twice its weight of cold water. 



202 MISCELLANEOUS PROCESSES. 

then apply heat to dissolve it ; stir 5 pounds tannin and 2 pounds 
soluble glass well into the glue, then add the alum solution. Enter 
the goods at 80° C, and steep 30 minutes. Take out and drain 
several hours, stretch on a frame, and, when dry, calender. 

A German shower-proof compound: Stir 9 pounds casein 
well in 32 quarts water, adding little by little 25 pounds of slaked 
lime. Add a solution of 4^ pounds soap in 26 quarts water. 

Filter and treat the cloth with the liquid. Dress with a 
dressing of acetate of alumina, by which the casein is rendered 
insoluble in the fibers of the cloth. After two applications, rinse 
the goods with hot water, press strongly, and dry. 

One process for waterproofing threads and yarns used in 
weaving ducks and other fabrics is in two parts, the first of which 
relates to a tanning mixture in which the yarns are immersed, 
consisting of : Birch bark, 14 pounds ; bichromate of potash, i 
pound ; chloride of calcium, ^ pound ; tar i pint ; solution of alkali, 
2 pounds. The threads are first boiled in a 5 per cent, solution of 
alkali to destroy perishable matter, after which they are immersed 
in the tanning liquid and dried. The second part consists of 
preparing or dressing the threads with the following compound: 

Poppyseed oil, 2 gallons; India-rubber solution, 2 pounds; 
red oxide of mercury, i pound ; resin, 28 pounds ; beeswax, 28 
pounds; palm oil, 14 pounds. The threads after this treatment 
are wound on reels for weaving. 

Forster, as far back as 1847, made a water-repellent com- 
pound in which he used spermaceti, wax, and stearine, while three 
years prior to that Townsend used two solutions to accomplish 
that end, the first being water, calcined British gum, white soap, 
logwood liquor, and rock alum ; the second being water, sulphate 
of zinc, calcined British gum, and palm soap. 

The Kyanized cloth process is well known in connection with 
preserving fabrics, the treatment being with a mixture of cor- 
rosive sublimate, chloride of zinc, pyrolignite of iron, oil of tar, 
and resinous matters. Fabrics treated in this way have been used 
for the manufacture of hose,. 

Crape cloth is a fabric which has much the appearance of real 
crape, but is far less expensive. It is treated with processes simi- 
lar to the Cravenette process, which make it both waterproof and 



DEODORIZATION. 203 

durable. Two patents for this process have been granted to W. 
E. B. Priestly. 

According to Dr. Doremus the lightest fabrics are rendered 
uninflammable by dipping them in a solution of phosphate of 
alumina in water. 

Allard^s fireproof felt is made of 50 per cent, of asbestos and 
50 per cent, of animal hair, and for ordinary purposes is wholly 
fireproof. 

Canvas for sails and other purposes, which it is desired to 
render waterproof, is treated by the Dumas process so that, while 
it is both waterproof and fireproof, it is still elastic and perme- 
able by air. The treatment is this : The material is first put in a 
solution of gelatine, then run through pressure rollers ,and spread 
in the open air to dry ; later it is dipped in a cold solution of alum 
again exposed to the air, then washed in cold water, and finally 
dried. 

Frankenburg's waterproof cloth is made in this manner: 
Both warp and woof are coated in the yarn with India-rubber, 
then powdered with farina, then woven, after which the fabric 
is calendered, and the result is a cloth that is thoroughly water- 
proof, and yet does not give evidence of having rubber in its 
make-up. 

Smith's porous waterproof fabric called for a compound 
made of 100 parts of paraffine melted by heat, to which was add- 
ed 15 per cent, of India-rubber, the mixture being kept from 5 
to 30 minutes at a temperature of 100° C. The solution, either 
as it is, or with a solvent, is then transferred to the cloth by means 
of a set of rollers which have a temperature of about 70° C. 

DEODORIZATION. 

The odors that cling to vulcanized rubber goods and to Gut- 
ta-percha are often very objectionable, and the following proces- 
ses are given for deodorization : 

Cattell's process: For every pound of well cleaned Gutta- 
percha take 15 pounds of the following solution: Benzole, i gal- 
lon ; alcohol, i ounce ; glycerine, 30 drops. Or : Benzole, i gallon ; 
nitrate of the oxide of ethyl, 30 drops; heat in a closed vessel 
to 110° F. The Gutta-percha is recovered by cooling to below 



204 MISCELLANEOUS PROCESSES. 

32° F., and pressing or by distilling off the solvent, or by precipi- 
tation with fusel oil. 

Freeley's process : Dip vulcanized rubber goods in a solution 
of : Salicylic acid, 20 grains ; alcohol, ^' pint. This will deodorize 
them, but goods will be toughened and the deodorization increased 
by subjecting goods to a bath in hot or cold solution composed 
as follows: 

(A) Bark of oak, 50 pounds; bark of hemlock, 50 pounds; 
bark of sumac, 50 pounds ; water, 900 gallons. 

(B) Solution as above, 2 gallons; salicylic acid, 20 grains; 
large tablespoonful of Russian Jackten extract, dissolved in 2 
pints of alcohol, i pint of ether, and 10 grains of salicylic acid. 

Bourne's process: The articles to be deodorized are placed 
between layers of charcoal and heated from 120° to 150° F., if 
unvulcanized ; 180° F. if partially vulcanized; or 212° F., if 
completely vulcanized. Heat for six hours or more. 

Lavater and Tranter's process: Subject the articles to a 
boiling in potash, then to a vacuum, then to a pressure of air 
scented with some essence. They claim the extraction of the sul- 
phur from the pores of the rubber in the form of sulphuretted 
hydrogen and its replacement by perfumed air. 

Charles Hancock's process: To remove the odor of Gutta- 
percha, steep it in the following solutions : 

(A) Soda or potash, i pound; water, 10 gallons. 

(B) Chloride lime, i pound; water, 10 gallons. 
De la Granja's process: 

Iodine 15 grains. 

Permanganate of potassa 20 grains. 

Iodide of potassium 60 grains. 

Glycerine 4 ounces. 

Sulphite of soda 4 ounces. 

Sulphite of lime 4 ounces. 

Sulphite of potassa 4 ounces. 

Water i>^ to 2 gallons. 

Steep or macerate rubber in a solution composed as above, 
in a close earthern vessel, 24 hours, the solution being cold. Then 
heat the solution gradually to boiling point and uncover the ves- 
sel until I of weight of solution evaporates. When the solution 
cools remove the rubber. 



PRESERVATIVE PROCESSES. 205 

PRESERVING RUBBER GOODS. 

The deterioration of vulcanized rubber goods is often a seri- 
ous matter, where it is necessary for some time to keep them in 
store. Wherever possible, they should be kept in a cool dark 
place, and away from warm currents of dry air. It has been ad- 
vised that such goods as druggists^ sundries be stored in an air- 
tight receptacle, in the bottom of which is placed a vessel contain- 
ing benzine, which is allowed to evaporate slowly. Kreusler and 
Bude in Der Techniker recommend the dipping of the articles in 
a paraffine bath, heated to about 212° F. This does not injure the 
color or the appearance, but is said to enable the goods to effectu- 
ally resist both light and atmospheric influences. From its well 
known softening effect on India-rubber, however, paraffine is like- 
ly to be used with considerable care by rubber manufacturers. 
In the line of mechanical goods. Turner patented a process for 
treating both hose and tubing with carbolic acid, either during its 
manufacture or after vulcanization in order to preserve it. Tor- 
rey also saturated duck with carbolic acid before it was made up 
into hose. 

Mowbray's process for preserving rubber in valves: The 
use of 20 pounds of India-rubber, washed and cut fine, in con- 
nection with 5 to 10 pounds of naphthaline ; digest 24 to 48 hours, 
at 180° to 230° F. Masticate in a machine heated to 212° F., 
until it forms a plastic homogeneous compound. If other sub- 
stances are to be added, treat as follows : 

1. Soluble matters (sulphur, antimony, resins, etc.) dissolve 
in naphthaline, melted or boiling, and add to above naphthalized 
caoutchouc at temperature of 240° F. 

2. Materials insoluble in naphthaline (oxides of lead and 
zinc, chalk, etc.) deprive of moisture and heat to 212° F. and add 
to naphthalized caoutchouc. 

This compound can be used for soft or hard rubber, accord- 
ing to the proportion of sulphur used. The object is to preserve 
the elasticity of rubber and prolong its durability. 

Trueman's process for preserving India-rubber, and fibers 
that may be used with it, employs the peroxides of manganese and 
lead and the black oxide of copper, all of which have the property 



2o6 MISCELLANEOUS PROCESSES. 

of decomposing ozone in great quantity, and converting it into 
oxygen. The inventor believes that ozone is the active agent in 
producing decay, and, by changing it into oxygen, he arrests such 
decay. In applying these oxides, he mixes them with ozocerite 
or tar. 

Elworthy patented a process for storing rubber goods in a 
receptacle filled with nitrogen, hydrogen, marsh gas, or carbonic 
acid gas. This was recommended especially for rubber goods m 
India. 

FASTENING RUBBER TO METALS. 

The problem often comes to rubber manufacturers as to how 
to stick rubber or rubber compounds to iron so that they will not 
part from it, no matter under what strain. This is done success- 
fully by a number of different formulas. Where the processes 
are skilfully carried out, the rubber should adhere so firmly to the 
iron, that it will disintegrate and give way anywhere else in the 
mass, except where its surface is in contact with the metal. The 
basis of all these processes is said to be the chemical affinity for 
sulphur which is in the rubber with the copper salts used in the 
compound. One formula for this is: First, the grinding of the 
iron, finishing it with a file, and dipping it in strong lye to re- 
move all grease, and afterward in muriatic acid or dilute sul- 
phuric acid heated in water. The metal is cemented before the 
rubber is applied. 

The process patented by Garrity and Avery, is as follows: 
Nitric acid (41° Baume), 10 gallons; muriatic acid (22° Baume), 
ID gallons; mix and add pure tin, finely divided, 10 pounds. 

Immerse the iron for 8 seconds, remove and dip into weak 
solution sulphuric acid, then wipe with a woolen cloth. Then 
apply with brush or otherwise, the following compound: Rubber 
cement, 7| gallons; litharge, 6 pounds; and sulphur, 3 pounds. 
Add vulcanizable rubber compound at once, and vulcanize. 

Hall's process : Water, 100 quarts ; caustic potash, 10 pounds ; 
cyanide of potash, 2 pounds; sulphate of copper, 2 pounds; sul- 
phate of zinc, 2 pounds. The pickle and bath are made of water 
and about 10 per cent, sulphuric acid, the tub being lined with 
brass plate. 



THE USE OF GASES. 207 

Adams's process: A weak solution of sulphate of copper is 
made — say 2 or 3 ounces of the crystalized salt to the gallon — 
and this solution may be acidulated with sulphuric acid — say 
about i gill of strong acid to the gallon. For a fine film for 
"dipping" articles of iron, steel, or tin, to which the rubber com- 
pound is to be applied, if the metal is copper, it should first be 
coated with tin, nickel, or iron. 

The Shellac process calls for a cement made of shellac steeped 
in ten times its weight of concentrated ammonia, the solution 
being allowed to stand three or four weeks. This solution is 
painted on the iron, allowed to dry, and the rubber vulcanized 
upon it. 

THE USE OF GASES. 

Before India-rubber reached its present value in the arts, 
and before coal gas was generally known as an illuminant, Mol- 
lerat obtained oil of caoutchouc by distillation and made a fine 
quality of illuminating gas from it. It is needless to say that the 
process is not practised to-day. 

Pellen rendered India-rubber impervious to gas by coating 
It with collodion mixed with a very small quantity of castor oil 
or with a varnish composed (i) of 32 per cent, of gum arable, 
8 per cent, of sugar, and 60 per cent, of water, or (2) made from 
28 per cent, of dextrin, 60 per cent, of water, and 12 per cent, of 
gelatine. 

Bousfield rendered vulcanized India-rubber impermeable to 
gias by applying linseed oil to it in the form of a varnish, the 
articles being heated. 

Parkes suspended articles to be vulcanized in a dry heater and 
passed the following gases into the chamber as a means of vul- 
canization: Sulphurous acid gas, chlorine, nitrous acid, or the 
vapors of bromine or iodine. 

Charles Hancock cured rubber by the action of vapors pro- 
duced by dissolving zinc, copper, or mercury in nitric acid. The 
action of these vapors being so solvent, only one or two moments 
were given, and the surfaces then washed in an alkaline solution. 

Nickels passed sulphur fumes and hydrogen into the gum 
while in a masticator, curing afterward by heat. 



2o8 MISCELLANEOUS PROCESSES. 

Johnson prepared carburet of hydrogen from oil of tar as a 
solvent for Gutta-percha. In order to overcome the smell of the 
solvent, he added a little alcohol in which was essence of lavender. 

Hughes made an artificial rubber from gelatine, resin, oil, and 
tannin, improving the compound by exposing the compound to 
the action of hydrogen, sulphurous gas, sulphuretted hydrogen, 
nitrous gas, or ammonia. 

Brooman treated vulcanized waste rubber with vapors of tur- 
pentine in his reclaiming process. 

Lake bleached India-rubber in a stream of ammonia gas or 
chloride of ammonia, afterwards thoroughly washing the gum in 
hot water. 

A great many rubber goods — ^that is, thin sheet goods — are 
cured by what is known as the vapor process. This is done in 
many cases by hanging the goods in an air-tight chamber, like a 
dry heater, and passing the vapor, which is either that of chloride 
of sulphur alone, or chloride of sulphur mixed with nitric acid, 
into the curing room. Small articles are often put in a tumbling 
barrel made of wire, which revolves slowly in the vulcanizing 
room, thus giving the vapor a chance to do its work thoroughly. 
The rubber surfaces are of course dusted first, to keep them from 
adhering. Proofed cloth is cured in vapor by passing the rubber 
surface over troughs in which this reagent is slowly evaporating. 

The vapors of ozocerite are also used in rendering cloth wa- 
ter-repellent. 

A mixture of chlorine and hydrogen gas is used for filling 
small India-rubber balloons. A fuse is attached to which a spark 
is applied before it is let off. After a time this spark reaches the 
gas, and the balloon explodes. 

Vulcanized India-rubber, whether compounded or pure, is 
permeable by gas. In making flexible gas tubing, therefore, it 
must be coated or in some way protected in order to make it gas 
tight. The common way of accomplishing this is to cover the 
rubber tube with an outer tube made of glue, glycerine, and bi- 
chromate of potash, this covering being protected in turn by a 
woven fabric. Another plan for accomplishing the same result 
is to have an outer and inner tube of India-rubber, between the 
two being vulcanized a sheet of tin-foil. 



METALS AND RUBBER. 209 

ACTION OF METALS ON RUBBER. 

The action of various metals on India-rubber has always in- 
terested rubber manufacturers. In the memoirs and proceedings 
of the Manchester (England) Literary and Philosophical Society, 
1890-91, William Thomson, F. R. S., and Frederick Lewis pub- 
lished an exceedingly interesting paper on this subject. They 
covered almost all of the metals that are likely in any way to come 
in contact with rubber surfaces, and proved what has long been 
acknowledged by rubber manufacturers, that the action of copper 
is most harmful. The metals that have no action at all on rubber 
are gold, silver, bismuth, antimony, arsenic, tin, chromium, iron, 
nickel, cobalt, zinc, and cadmium. Those that act only in a slight 
degree on rubber are lead, aluminum, palladium, and platinum. 

Of the salts of metals that are very destructive, copper stands 
first, manganese oxides and nitrate of silver, being, however, al- 
most as bad. Several other nitrates have also an injurious effect, 
although not as much so as those just mentioned. They are the 
nitrates of ammonia, uranium, sodium, and iron. 

According to N. Foden, a well-known English expert, proof- 
ed goods in browns have caused him more trouble by deterioration 
than any other colors — more than black, even — and it is to be 
said right here that blacks as a rule are viewed with distrust by 
manufacturers, because it is believed generally that copper salts 
are used in the dyeing. Mr. Foden instances the time when brown 
tweeds were used largely, and when most manufacturers experi- 
enced a great deal of trouble with them, as the browns showed 
early signs of decay, while the grays remained soft and flexible. 
Mr. Foden suggests that, as certain dyers use lime, which is 
cheaper than logwood, this may act destructively upon the rubber. 

ARTIFICIAL RUBBER MILK. 
When rubber in solution of almost any of the ordinary sol- 
vents is mixed with a moderately large quantity of methylated 
vSpirit, it is precipitated and forms later a sticky, whitish mass 
from which the resins and coloring matter have been taken by the 
spirit. Instead of this process, Lascelles-Scott advises the fol- 
lowing: Take a 10 or 15 per cent, solution of fine Para rubber in 
benzine or chloroform with a little strong alcohol, but not enough 
to precipitate the rubber. If a considerable volume of tepid water 



2IO MISCELLANEOUS PROCESSES. 

be then quickly stirred into the solution, the rubber slowly sepa- 
rates from its solvent. If to this is added a little resin-potassa 
soap, with a little liquor ammonia, the emulsion is very similar 
to rubber milk. The distinguished author suggests the use of 
potassa soap made of the native rubber resin as the best emulsi- 
fying compound for such a purpose. 

In writing on the preservation of genuine rubber milk, he 
also condemns the use of creosote, for, although it prevents fer- 
mentation, it does not hinder the gum from separating. He ad- 
vises the use of ammonia and if it is to be kept through hot wea- 
ther, the addition of a fragment of camphor or naphthaline or a 
few drops of santal-wood oil. 



SHRINKAGE OF RUBBER. 211 

SHRINKAGE OF RUBBER. 

The following table shows the average rate of shrinkage in 
the various leading grades of India-rubber, and also the widest 
range of shrinkage noted in the practice of some extensive manu- 
facturers. The figures express percentages in weight : 

Average. Range. 

Para sorts : 

Fine 16 to 18 15 to 20 

Medium 17 to 19 16 to 22 

Coarse. 22 to 28 18 to 35 

Mangabeira 25 to 30 20 to 35 

Caucho 26 to 34 20 to 40 

Centrals 26 to 32 20 to 40 

Africans : 

Tongues 19 to 24 18 to 25 

Flakes 28 to 33 25 to 35 

Thimbles 22 to 28 15 to 35 

Accra sorts 24 to 32 20 to 40 

Congo sorts 19 to 24 18 to 35 

Benguella sorts 16 to 20 16 to 20 

Mozambique sorts 17 to 28 to to 35 

Madagascar sorts 30 to 40 25 to 55 

Assam 23 to 31 8 to 45 

Borneo 33 to 38 30 to 45 

Mr. T. Bolas, in his "Cantor lectures" on India-rubber, in 
1880, gave the following estimates of shrinkage of these leading 
Sfrades : 



Para 15 P^^ cent. 

Para negroheads 25 

Ceara 28 

Guayaquil 40 

Borneo 25 

African ball 25 

African tongues 35 

African niggers 25 

Madagascar 25 

PARA RUBBERS. 

The next table indicates in detail the percentage of shrink- 
ages in the various grades of Para rubber , also determined by the 
practice of American manufacturers : 

Fine. 

Bolivian 15 to 17 

Mollendo 15 to 17 

Madeira 15 to 18 

Manaos 16 to 17 



Medium. 


Coarse. 


16 to 18 


20 to 25 


16 to 18 




16 to 19 


20 to 25 


17 to 18 


18 to 22 



212 SHRINKAGE OF RUBBER. 

Upriver i6 to i8 17 to 19 18 to 25 

Matto Grosso 16 to 18 17 to 19 20 to 28 

Angostura 16 to 18 17 to 19 25 to 30, 

Caviana 16 to 18 18 to 20 25 to 30 

Itaituba 17 to 18 18 to 19 20 to 25 iiaj^ 

Islands 18 to 20 18 to 22 25 to 35 .1,,;,,.^,^^ 

Cameta 30 to 35 

The shrinkage of Mangabeira (Pernambuco) thin sheet is 
about 25 to 30 per cent. ; thick sheet, 30 to 35 ; ball, 20 to 25. 
Caucho (Peruvian) slab, 30 to 40; sheet, 30 to 35; strip, 25 to 
35 ; ball, 20 to 25. 

The better grades of Centrals shrink from 25 to 30 per cent. ; 
other grades, generally from 30 to 40. 

AFRICANS. 

The Gold Coast sorts (including Accra, Cape Coast, Saltpond, 
Addah, Quittah, and Axim) range about as follows: Buttons or 
biscuit, 20 to 30; flake, 30 to 35 ; lump, 30 to 40; niggers, 20 to 35. 

Cameroon ball, 18 to 25 ; clusters, 18 to 28. 

Lagos buttons, 25 to 35; lump, 30 to 40; strip, 25 to 35. 

Congo buttons, 25 to 30; ball No. i, 20 to 25; ball No. 2, 
25 to 35 ; Upper Congo ball and strips, 20 to 25 ; red ball, 18 to 
22; Equateur small ball, 16 to 20; mixed ball, 18 to 22; Lopori 
small ball, 16 to 22; Kassai black twist, 18 to 22; red twist, 20 to 
25 ; ball, 20 to 25. 

Benguella (and Loanda) sausage, 16 to 20 ; niggers, 18 to 20. 

Mozambique (including Lamu) ball No. i, 10 to 15; ball 
No. 2, 15 to 25 ; ball No. 3, 25 to 35 ; sausage, 20 to 35. 

Madagascar pinky, 30 to 35 ; Majunga, 30 to 35 ; black, 30 
to 40 ; niggers, 30 to 40. 

EAST INDIAN. 

Assam No. i, 10 to 15 ; No. 2, 20 to 30; No. 3, 30 to 35. 
Penang, No. i, and Java No. i, 10 to 15 per cent.; other 
numbers same shrinkage as Assam. 

E. Chapel gives this table of percentages of shrinkage : 

Para, fine 12 Ceara 28 

Para, coarse 25 African ball \ 28 

Loando 17 Madagascar 28 

Colombia 20 Assam 28 

Java. 22 Gaboon 35 

Gambia 24 Borneo 35 



SHRINKAGE OF RUBBER. 213 

TO FIGURE SHRINKAGE IN CRUDE RUBBER. 

It is strange that there should be a divergence of opinion 
and method in arriving at the net cost of rubber after washing, 
sheeting, and drying it, yet such is the case. To assist those who 
have not studied this question, the right and the wrong way of 
figuring on shrinkage is given here. Take for instance an ave- 
rage-priced rubber: 

Example A. 
100 lbs. rubber at $0.50 = $50.00 
20 lbs. shrinkage = 20 per cent., or i-5th. 



80 lbs, net cost $50.00, as above. 

80) 50.00 (62.50 
48 o 



200 
160 



400 
400 



Some persons, however, figure in this way: 

Example B. 
100 lbs. at $0.50 lb. 
Shrinkage 20 per cent. = i-5th. 
$0.50 -j- i-5th (10 cents) = 60 cents. 

Example A. — Correct method — net cost 62.50 

Example B. — Incorrect method — net cost 60.00 

DiflEerence 2.50 

This is a difference of 4 per cent., which, if it occurs in manu- 
facturing a large amount of goods where rubber is the greater 
part of the compound, would make quite a difference in the profit. 

SPECIFIC GRAVITY OF RUBBER. 

The following records of the specific gravities of different 
samples of India-rubber have been collected: 

Best Para, taken in dilute alcohol (Ure) 0.941567 

Best Assam, taken in dilute alcohol (Ure) 0.942972 

Best Singapore, taken in dilute alcohol (Ure) 0.936650 

Best Penang, taken in dilute alcohol (Ure) 0.919178 

Caoutchouc (Julian) 0.920000 

Crude caoutchouc of India (Adriani) 0.966800 



214 SHRINKAGE OF RUBBER. 

Black caoutchouc (Adrian!) 0.945200 

Prepared from juice in pure state (Faraday) 0.925000 

Determined by E. Soubeiran 0.935500 

Determined by Payen 0.925000 

H. L. Terry, F. I. C, gives the specific gravity of Para rub- 
ber and refers to Faraday^s figures as being most correct. 
Faraday's general analysis of the sap of the Hevea is : 

Caoutchouc 30.70 

Albuminous extractive and saline matter 12,93 

Water 56-37 

The specific gravity of the sap quoted was 1.012. 
The crude rubber itself is made up of the following general 
composition : Carbon, 87.5 ; hydrogen, 12.5. 



CHAPTER XIII. 

PHYSICAL TESTS AND METHODS OF ANALYSIS OF VULCANIZED INDIA- 
RUBBER. 

It has long been the boast of expert rubber superintendents 
and manufacturers that they found little trouble in matching com- 
pounds. As a matter of fact, some of them are marvelously ex- 
pert. Given a small sample of vulcanized rubber in a familiar line, 
with a knowledge of the price at which it must be produced, they 
are able in a majority of instances, by their knowledge of rubber 
and of compounding ingredients, to get a result that is apparently 
similar, and without much experimenting. 

In certain instances, however, they fail, principally where a 
new product is brought in for matching, to which is attached an 
extraordinarily low price. The usual refuge in such a case for- 
merly was the assertion that the manufacturer was losing money 
on that particular line of goods. But this has been so often dis- 
proved, and the sample found to be both an original and better 
compound, that this excuse is not often heard nowadays. 

The factory expert gaged his sample, no matter how expert 
he might be, by purely physical rules. The smell told him what 
kind of rubber was used, whether Para or African, and usually 
whether reclaimed rubber was present. The strength and the 
weight of the sample gave him an indication as to the amount 
of adulteration. The color also had its suggestions as to material 
contained in it, but the knowledge thus shown often was very far 
from being exact. 

Nor was the general result very much better when informa- 
tion was purchased from employes, or points secured through 
quizzing the supply men. The best course for the rubber super- 
intendent to pursue, therefore, is to put his knowledge up against 
that of the expert chemist, when the two, working together, can 
usually match better than the original. It is better, if the chemist 
is familiar with the practical manipulation of rubber, for the un- 
familiar chemist has in many cases brought science into consider- 
able disrepute in the factory. 

Certain rubber compounds, in spite of the most careful analy- 
sis 



2i6 ANALYSES OF RUBBER. 

sis by expert chemists, have remained, and probably will remain, 
profound secrets. For ordinary work, however, there ought to 
be no trouble in getting a fair analysis. The following descrip- 
tions of processes employed in the analysis of vulcanized rubber 
are given chiefly that the rubber superintendent who views chem- 
istry as a dark and deep mystery may have some knowledge of 
what the chemist is about when he seeks his assistance. Before 
beginning on chemical analysis a few words more concerning 
physical tests may not be amiss. 

In the case of many kinds of goods there is a great variety 
of appliances that form really valuable tests as to their durability, 
tensile strength, wearing quality, etc. As a rule, these aim to 
reproduce the work that the vulcanized article is obliged to en- 
dure in actual service. In rubber boots and shoes,- for example, 
a machine is employed which bends the shoe exactly as it is bent 
when the wearer is walking, and at the same time gives a friction 
motion on the sole. This is run at a high rate of speed, so that a 
week's wear on a machine like this would correspond to a month 
of service in actual use. 

A machine is also used for testing air-brake hose which coun- 
terfeits the swing and kinking motion that the hose gets in actual 
service. This is run at a very high rate of speed, and the hose 
which stands this sort of usage longest is supposed to be adapted 
to endure the longest time in actual use. 

Tires, both pneumatic and solid, are tested by being put on a 
wheel rim and run what is equivalent to hundreds and thousands 
of miles over roughened surfaces upon which they are pressed by 
a lever carrying heavy weight. These mechanical contrivances 
are valuable in showing the severe usage that rubber will often 
stand, but none of them are exact parallels to absolute service, 
for as a rule they are more severe, particularly in the intense heat- 
ing that may come to the rubber from high speeds and great fric- 
tion. 

Manufacturers and purchasers of rubber goods have also 
many simple and excellent tests for approximating the value of 
the rubber. In belt and hose covers and tubes, a bit of the rubber 
is cut from the fabric and stretched to show its tensile strength. 
The fabric is also pulled apart, and the integrity of the friction 



TESTS OF VULCANIZED RUBBER. 



217 



proved by the way it resists such separation. Rubber springs 
sometimes have been placed under a steam hammer which was 
allowed to drop upon them, the results being noted and that com- 
pound standing up longest being considered the best. 

An English manufacturer following out this test, got some 
interesting, if not valuable, results. He took a piece of vulcanized 
India-rubber i^ inches thick and with 2 inches area, and placed it 
under a steam hammer of five tons, which first rested upon the 
rubber without effect. The hammer was then raised two feet and 
dropped upon it without injury; then lifted four feet, when the 
cake was torn, but none of its elasticity was destroyed. More se- 
vere trials were then made. A block of vulcanized Inlia-rubber 
was placed between two cannon balls, with the whole power of 
the heaviest steam hammer employed; the iron spheres split the 
block, but the elasticity of the rubber still remained. 

The ordnance department of the United States government 
some years ago inaugurated some very interesting tests of vul- 
canized rubber at the arsenal at Watertown, Mass., the results 
of which are appended : 



No. 1. 



Applied Loads. 


Mean Length. 


Compression. Compr 


sssion Sets. 


Middle Diameter. 


Pounds. 


Inches. 


Inches. 1 


nch. 


Inches. 





S.I2 






6.10 


1,000 


5-32 


.40 




6.3S 


2,000 


4.84 


.88 


10 


6.72 


3,000 


4-47 


1.25 


18 


7.06 


4,000 


4-03 


1.69 


29 


7.48 


5,000 


3-70 


2.02 


33 


7-79 


6,000 


3-40 


2.32 


37 


8.12 


7,000 


3-14 


2.58 


42 


8.44 


8,000 


2.96 


2.76 


39* 


8.73 


9,000 


2.80 


2.92 


51 


8.92 


10,000 


2.68 


3-04 


58 


9.11 


11,000 


2.60 


3.12 


52* 


9.24 


12,000 


2.50 


3.22 


60 


9.42 


13,000 


2.45 


3-27 


67 


9-55 


14,000 


2.36 


3-36 


73 


9.68 


15,000 


2.31 


3-41 


74 


9-77 





5.15 






6.71 



*Before these sets were taken the load on the rubber was reduced to 500 pounds, then 
increased to 1,000 pounds, and the sets then measured. 



2l8 



ANALYSES OF RUBBER. 



The second test was of new rubber gun-carriage springs, in 
which the compression sets were determined under the initial load, 
the end diameters approximate under load. The length of the 
rubber spring was 6.03 inches ; the diameter 6.03 inches ; the dia- 
meter of core 1.04 inches; the sectional area 27.71 square inches; 
and the weight 11 pounds: 



No. 2. 



Applied 


Length. 


Compres- 
sion. 


Compres- 
sion Sets. 


Diameters. 


Middle 


Loads. 






Diam. Under 










End. 


Middle. 


Initial Load. 


Founds. 


Inches. 


Inches. 


Inch. 


Inches. 


Inches. 


Inches. 


500 


5-87 


0. 


0. 


6.03 


6.12 


6.12 


1,000 


5.70 


•17 


.02 


6.03 


6.24 


6.15 


1,500 


5-51 


•36 


•03 


6.03 


6.35 


6.15 


2,000 


5-34 


•53 


.06 


6.03 


6.48 


6.18 


2,500 


5-13 


• 74 


•07 


6.03 


6.64 


6.18 


3,000 


5-00 


.87 


.07 


6.10 


6.76 


6.18 


3,500 


4.81 


1.06 


.09 


6.15 


6.87 


6.18 


4,000 


4-65 


1.22 


.08 


6.16 


7.00 


6.18 


4,500 


4- 50 


1-37 


.08 


6.18 


7-15 


6.19 


5,000 


4-35 


1.52 


.02 


6.29 


7.26 


6.19 


5,500 


4.20 


1.67 


.12 


6.38 


7^4i 


6.19 


6,000 


4.06 


1.81 


.19 


6.43 


7-55 


6.19 


6,500 


3-95 


1.92 


•03 


6.50 


7.66 


6.21 


7,000 


3.83 


2.04 


•15 


6.64 


i-n 


6.21 


7,500 


3-70 


2.17 


•15 


6.70 


7.91 


6.22 


8,000 


3.62 


2.25 


•15 


6.78 


8.02 


6.22 


8,500 


3-52 


2.35 


.16 


6.89 


8.13 


6.22 


9,000 


3.43 


2.44 


.16 


6.96 


8.24 


6.23 


9,500 


3-35 


2.52 


•17 


7.06 


8.34 


6.24 


10,000 


3-25 


2.62 


.17 


7^25 


8.46 


6.25 



The spring was then removed from the testing-machine, 
measured, and its length was 5.90 inches; middle diameter 6.08 
inches. After it had rested 20 minutes the length was 6 inches, 
and the middle diameter 6.06 inches. It was then placed again in 
the testing machine and the figures on the following page taken . 

When removed its measurements were: Length 5.86 inches; 
middle diameter 6.24 inches; end diameter 5.90 inches; the ends 
were concave, V. sine .06 and .08 inches. After six hours rest it 
recovered in length to 5.96 inches. 



TESTS OF VULCANIZED RUBBER. 



219 



No. 3. 











Diameter. 


Middle 


Applied 
Loads. 


Length. 


Compres- 
sion. 


Compres- 
sion Sets. 






Diam. Under 
Initial Load. 


Ends. 


Middle. 


Pounds. 


Inches. 


Inches. 


Inch. 


Ijiches. 


Iftches. 


Inches. 


500 


5.84 


•03 


• 03 


6.01 


6.15 


6.15 


6,000 


4.00 


1.87 




6-55 


7.63 




10,000 


3-29 


2.58 




7-25 


8.40 




10,500 


3.21 


2.66 




7-35 


8.48 




11,000 


3.16 


2.71 




7-39 


8.54 




11,500 


3-II 


2.76 




7.46 


8.60 




12,000 


3.06 


2.81 


• 17 


7-55 


8.67 


6.26 


13,000 


2.94 


2.93 




7-74 


8.86 




14,000 


2.86 


3.01 




7.86 


8.97 




15,000 


2.80 


3-07 


.22 


7-94 


9.04 


6.30 


16,000 


2.71 


3.16 




8.10 


9.20 




17,000 


2.65 


3.22 




8.20 


9.28 




18,000 


2.61 


3.26 




8.27 


9-35 




19,000 


2.56 


3-31 




8.36 


9.42 




20,000 


2.53 


3-34 


•30 


8.43 


9-47 


6.37 



In the next test the length of the spring was 6.06 inches; 
diameter, 5.97 inches; diameter of core 1.06 inches; sectional area 
27.11 square inches; weight, 11 pounds. 



No. 4. 



Applied 
Loads. 


Length. 


Compres- 
sion. 


Compres- 
sion Sets. 


Diameter. 


Middle 


End. 


Middle. 


Diam. Under 
Initial Load. 


Pounds. 


Inches. 


Inches. 


Inch. 


Inches. 


Inches. 


Inches. 


500 


5-90 


0. 


0. 


5-97 


6.07 


6.07 


1,000 


5-75 


• 15 


.02 


5-97 


6.16 


6.07 


1,500 


5.59 


•31 


.02 


5.97 


6.27 


6.08 


2,000 


5.41 


• 49 


.06 


5.98 


6.38 


6.10 


2,500 


5-25 


.65 


.05 


6.02 


6.48 


6.10 


3,000 


5.05 


.85 


.09 


6 05 


6.62 


6.12 


3,500 


4.90 


1. 00 


.08 


6.08 


6.73 


6.11 


4,000 


4.76 


1. 14 


.10 


6.14 


6.88 


6.12 


4,500 


4.61 


1.29 


.10 


6.20 


7.00 


6.12 


5,000 


4-47 


1-43 


.11 


6.25 


7.11 


6.12 


5,500 


4-33 


1-57 


.11 


6.31 


7.24 


6.14 


6,000 


4.21 


1.69 


.12 


6.37 


7.32 


6.15 



The measurements when removed from the machine were: 
Length, 5.98 inches ; middle diameter 6 inches ; end diameter 5.97 
inches. After it had rested 15 hours, it measured length 6.02 in- 



220 



ANALYSES OF RUBBER. 



ches ; middle diameter 6 inches ; end diameter 5.96 inches. It was 
then placed again in the machine and tests were resumed. 



NO. 5. 



Applied 


Length. 


Compres- 
sion. 


Compres- 
sion Sets. 


Di.imeter. 


Middle 


Loads. 


End. 


Middle. 


Diam. Under 
Initial Load. 


Pounds. 


Inches. 


Inches. 


Inch. 


Inches. 


Inches. 


Inches. 


500 


5-90 


0. 




5.97 


6.08 


6.08 


6,000 


4.27 


1.63 




6.35 


7.30 




6,500 


4.12 


1.78 


.08 


6.38 


7.41 


6. II 


7,000 


4.00 


1.90 


.09 


6.50 


7.55 


6.12 


7,500 


3-90 


2.00 


.10 


6.57 


7.62 


6.14 


8,000 


3.82 


2.08 


.10 


6.65 


7-73 


6.12 


8.500 


3-72 


, 2.18 


.11 


6.75 


7.82 


6.14 


9,000 


3.62 


2.28 


.14 


6.84 


7-93 


6.16 


9.500 


3-52 


2.38 


.14 


6-93 


8.03 


6.17 


10,000 


3-45 


2.45 


.16 


7.00 


8.11 


6.17 



The spring was then removed from the testing machine and 
its measurements were: Length, 5.92 inches; middle diameter, 
6.09 inches. Measurements after the spring had rested one hour 
showed: Length, 5.98 inches; middle diameter, 6.06 inches; end 
diameter, 5.95 inches. The spring was again placed in the ma- 
chine and tests resumed. 



No. 6. 



Applied 


Length. 


Compres- 


Compres- 


Diameter. 


Middle 


Loads. 




, 


Diam. Under 










End. 


Middle. 


Initial Load. 


Pounds. 


Inches. 


Inches. 


Inch. 


Inches. 


Inches^ 


Inches. 


500 


5.88 


.07 


.07 


5-97 


6.13 


6.13 


6,000 


4.09 


1. 81 




6.41 


7.47 




10,000 


3-46 


2.44 




7.00 


8.12 




10,500 


3.38 


2.52 




7.09 


8.22 




11,000 


3-34 


2.56 




7-15 


8.27 




11,500 


3.27 


2.63 




7.21 


8.36 




12,000 


3-17 


2.73 


.22 


7.26 


8.40 


6.22 


13,000 


3.10 


2.80 




7.46 


8.57 




14,000 


3.02 


2.88 




7-51 


8.67 




15,000 


2.90 


3.00 


.26 


7.66 


8. 70 


6.27 


16,000 


2.84 


3-o6 




7.84 


8.95 




17,000 


2.79 


3-II 




7.90 


9.02 




18,000 


2.75 


3-15 




7.97 


9.06 




19,000 


2.70 


3.20 




8.05 


9-13 




20,000 


2.68 


3.22 


.37 


8. II 


9.19 


6,36 



TESTS OF VULCANIZED RUBBER. 



221 



[the preceding table continued.] 



Applied Loads. 


Length. 


Compres- 
sion. 


Applied Loads. 


Length. 


Compres- 
sion. 


Pounds. 


Inches. 


Inches. 


Pounds. 


Itiches. 


Inches. 


l,ooo 


5-43 


■ 47 


11,000 


3-05 


2.85 


2,000 


5.IO 


.80 


12,000 


2.98 


2.82 


3,000 


4-75 


1. 15 


13,000 


2.91 


2.99 


4,000 


4-43 


1.47 


14,000 


2.85 


3-05 


5,000 


4.10 


1.80 


15,000 


2.81 


3-09 


6,000 


3.80 


2.10 


16,000 


2.78 


3.12 


7,000 


3-58 


2.32 


17,000 


2.74 


3.16 


8,000 


3-38 


2.52 


18,000 


2.70 


3.20 


9,000 


3-25 


2.65 


19,000 


2.67 


3-23 


10,000 


3-15 


2.75 


20,000 


2.63 


3-27 



Time for loading three minutes. The spring was then re- 
moved from the testing machine and its measurements showed : 
Length, 5.81 inches; middle diameter, 6.25 inches; end diameter, 
5.87 inches; ends concave, V. sine, .08 and .10 inch. It recovered 
in length to 5.93 inches after four hours' rest. 

The French navy also inaugurated a series of tests for rub- 
ber belting which are of interest. The first test related to elas- 
ticity. Samples from the cover were first put into a steam vul- 
canizer for 48 hours, under a pressure of 5 atmospheres, which 
they shouW stand without losing their elasticity. The samples are 
then placed under a pressure of 85.5 pounds per square inch on 
the grating of a valve box, and given strokes at the rate of 100 
per minute. They were expected to stand 9,100 strokes, while 
samples not tested by the steam should stand 17,100 strokes. 
Strips from the cover that had received the steam treatment, 6-10 
of an inch square on cross section, and 8 inches long, fastened 
at each end and elongated 3.9 inches, were not expected to break 
when stretched to 8 inches more, this being repeated 22 times a 
minute for 24 hours. Strips that had not been treated to the steam 
bath, should resist the same treatment for 100 hours. These tests 
of course applied to high grade compounds only. 

The analysis of vulcanized India-rubber should give the fol- 
lowing information: 

Amount of India-rubber, 
Amount of India-rubber resins, 
Amount of substitutes, 



222 ANALYSES OF RUBBER. 

Amount of free, fatty resin, and mineral oils, resin, paraffine, and 
bituminous bodies, 

Amount of sulphur of vulcanization. 
Amount of sulphur and chlorine in substitute, 
Amount of free sulphur, 
Amount of mineral matters. 

The mineral matters embrace metallic sulphides and oxides, 
inert mineral substances such as whiting and barytes, and sub- 
stances imparting special properties such as asbestos, graphite, 
pumice, etc. 

According to Carl Otto Weber, Ph. D., F. C. S., and to Percy 
Carter Bell, F. I. C, F. C. S., Dr. Rob. Henriques has by his 
methods of analysis solved the problem that troubled the analysts 
more than any other, which was that of determining the amount of 
oil substitutes found in India-rubber compounds. 

Dr. Henriques's methods are as follows : Fuming nitric acid 
to the amount of 20 c. c, is placed in a small dish covered with 
a funnel, through the stem of which 3 to 4 grams of rubber are 
slowly added. When the action has ceased, the dish is warmed 
gently on a water bath until the contents are of the consistency 
of a thin syrup. There is then added 4 grams of a mixture of 4 
parts of sodium carbonate and 3 parts of potassium nitrate, after 
which it is carefully fused, and treated with dilute muriatic acid, 
then evaporated to dryness to render silica, if present, insoluble, 
redissolved by adding a little nitric acid, and, last, the sulphuric 
acid is precipitated with barium chloride. The residue of silica 
may contain sulphates of lead or of barium. Ammonium acetate 
dissolves the former. 

In estimating the sulphur of vulcanization, and also the ex- 
cess of sulphur, they must be separated from that present in the 
form of sulphates and sulphides. This is done in the following 
manner : The sample of rubber is dissolved in that fraction of or- 
dinary petroleum which distills over at from 140° to 250° C, being 
kept in the solvent at a boiling temperature for two days. From 
5 to 15 grams of the sample are placed in a weighed flask, and, 
after adding about 150 c. c, petroleum free from sulphur, all the 
inorganic matter is dissolved by heating the flask with reflux con- 
denser at about 1 50° C. The subsequent processes are the filtering 
of the solution, the careful washing of the flask with hot petro- 



TESTS OF VULCANIZED RUBBER. 223 

leum, and the rinsing of both flask and Alter with petroleum ether. 
Those substances insoluble in petroleum are determined by 
weighing on the tared filter at 110° C. 

The sulphur in this residue which is easily determined, when 
deducted from the total sulphur of the sample, gives the amount 
of the free sulphur, and sulphur of vulcanization. If the rubber 
contains metallic oxides or carbonates, some of the sulphur may 
have been oxidized to sulphuric acid, and the results noted above 
may be too low. 

The rubber substitutes in the compound are completely and 
easily soluble in alcoholic potash. The following is the manner 
of this analysis: From 3 to 5 grams of the rubber compound, 
finely divided, is boiled for about 8 hours in ten times its weight 
of alcoholic soda, 8 per cent, strong. The solution, diluted with 
water, is freed from the alcohol by means of a water bath, after 
which the residue on a weighed filter is washed, dried, and weigh- 
ed. To determine the residue or ignition of the extracted residue, 
one gram is taken and the ignition performed in the presence of 
ammonium nitrate. If now the substance extracted from the rub- 
ber is free from chlorine, it may either consist of free oil, or be de- 
rived from black rubber substitute. In the latter case, it must con- 
tain at least 10 per cent, of sulphur, but in the former, only traces 
of sulphur will be present. An estimation therefore of the chlorine 
and of the sulphur in the alcoholic extract determines the pres- 
ence of white substitute, black substitute, or sulphur. 

In using caustic alkali a certain amount of the alkali will be 
retained, the amount of which must be determined, if correct 
figures are to be secured. Repeated washings in dilute muriatic 
acid remove this, and allow of its determination. 

The following data are necessary in the analysis of vulcan- 
ized rubber containing substitute or oil: (i) The total sulphur; 
(2) the total ash; (3) the weight of the substance after extrac- 
tion with alcoholic soda; (4) the sulphur, the ash, and the sul- 
phur in the extracted fatty acids all to be found in the third sub- 
stance. Also, the weight of the substance after extraction with 
alcoholic soda. From 1.5 to 2 grams of substance are used, the 
extraction being twice repeated, each boiling being from two to 
three hours. The quantity of rubber dissolved by the alcoholic 



224 ANALYSES OF RUBBER. 

soda is deducted from the weight of the total extract. This cor- 
rection averages 2.5 per cent. 

From the above figures, the percentage of rubber and fatty 
acids may be calculated by equations, which read : 

100 

Rubber = (Weight of substance after extraction of alcoholic 

97.5 soda — its sulphur — its ash). 

The fatty acids from this equation : 

Fatty acids = 100 — (total sulphur + total ash + percentage of 

rubber found from the foregoing equation). 

The sulphur contained in the rubber substitute is represented 
by assuming that quantity to be about equal to that of the fatty 
acids in white substitute and about 1.5 per cent, larger than the 
quantity of fatty acids in brown substitute. The difference be- 
tween the total sulphur and the sulphur in the substitute is the 
sulphur of vulcanization. Asphalt being often present in rubber 
compounds, by first dissolving the free sulphur by treatment with 
alcoholic soda, and then dissolving the asphalt out by means of 
nitrobenzene, it is easily determined. The presence of mineral oils, 
paraffine, and resins are the only things that interfere with this 
means of extraction. 

The following tests are credited to C. A. Lobuy de Bruyn : 

1. Extract Test. — (Henriques's method). — Three grams 
of the finely divided sample wlien boiled for six hours with 50 c. c. 
of a 6 per cent, alcoholic solution of caustic soda should not lose 
more than 8 per cent., the loss to be calculated upon the organic 
substance of the sample. The extract should contain sulphur and 
rubber resins. 

2. Dry Heat Test. — Two grams of the finely divided sam- 
ple are heated to 135° C. for two hours. When cold the sample 
should not have suffered any alteration and should show a loss of 
weight not exceeding 1.5 per cent. 

3. Moist Heat Test. — A small piece of the sample is sealed 
in a glass tube half filled with water. The tube is then heated 
to 170° C. for four hours. The sample should not be affected by 
this treatment. 

4. Ash. — About i gram of the sample is fused, decomposed, 



REINHARDTS METHOD. 225 

and partly ignited over a small flame in a porcelain crucible. The 
heat is then increased and ignition completed. 

Dr. C. Reinhardt, in Dingler's Polytechnisches Journal, 
writes as follows on the analysis of vulcanized India-rubber : "The 
determination of the ashes is effected by gradually heating in a 
covered crucible .0182 ounce of the product until aie cessation of 
gaseous liberation. The calcination is finished in an open crucible, 
care being taken not to heat too much, so as to avoid the losses 
due to the volatilization of the substances composing the ashes. 
To determine the proportion of mineral substances (with the ex- 
ception of sulphur) .0182 ounce of India-rubber fragments is 
moistened with 1.2 cubic inch of D nitric acid (= 14. and heating 
takes place in a water bath for five to seven minutes, until com- 
plete dissolution ensues. Dry evaporation takes place in the 
water bath, followed by moistening with hydrochloric acid and 
dissolution in water. The residue is formed of sulphate of 
barium and silica acid; the quantitative analysis of the sub- 
stances contained in the liquid (oxide of zinc, lime, magnesia, 
oxide of iron, and alumina) being made according to the usual 
methods. To determine the total of sulphur there is treated 
.0357 ounce of the product (while heated) with 1.2 cubic inches 
of nitric acid ; chlorate of potash being gradually added until oxi- 
dation is complete. After evaporation and dissolution in water, 
with the addition of hydrochloric acid, follows precipitation. Then 
takes place, the quantitative analysis of the sulphuric acid by the 
chloruret of barium and of the remainder of the sulphuric acid in 
the insoluble residue of sulphate of baryta. It is possible to deter- 
mine the quantity of sulphur added for the vulcanization by burn- 
ing the product in a current of oxygen at a low temperature by 
passing the vapors across hydrochloric acid containing bromine, 
and by analyzing quantitatively the sulphuric acid formed in the 
condition of sulphate of baryta. The India-rubber can likewise 
be distilled in glass tubes and the quantity ol sulphur in the dis- 
tilled liquor can be ascertained." 

Dr. Weber^s exceedingly valuable article printed in the Jour- 
nal of the Society of Chemical Industry is probably the most com- 
prehensive treatment that the subject of the analysis of vulcanized 
rubber has yet received. The steps in that analysis are thus shown : 



226 ANALYSES OF RUBBER. 

SUMMARY OF WEBER'S METHODS OF ANALYSIS. 

I. Acetone (lo runs in Soxhlet tube). 



Fatty and 

Mineral 

Oils, 

Resins and 

Free 

Sulphur. 



II. Boiling Alcoholic Soda (8 per cent). 



Rubber 
Substitutes. 



III. Cold Nitrobenzole. 



Asphaltum. 



IV. Boiling Nitrobenzole (Soxhlet 
tube). 



Rubber and 
Sulphur 
of Vul- 
canization. 



V. Residue. 



Mineral matters and 
free carbon. 



The rubber substitutes are determined by extracting in alco- 
holic soda solution and asphaltum by cold nitrobenzene, both of 
these methods being Henriques's. The rubber is separated by 
extraction with boiling nitrobenzene in the Soxhlet tube. Starch 
is dissolved out by boiling water. The mineral and carbonaceous 
matters are determined in the final residue. The matters in the 
acetone extract, the rubber and mineral matters are determined by 
weighing after evaporation. Substitutes and asphaltum are best 
determined in the loss of weight operated upon. 

Of the various forms of sulphur occurring in rubber, the 
determination of free sulphur and sulphur of vulcanization, is of 
great importance. The estimation of the free sulphur is made in 
the acetone extract. Not all the sulphur in this extract is free, as 
the presence of rubber substitutes in the sample means that the 
extracts will contain sulphides of the fatty acids, also the sul- 
phides produced by the action of free sulphur on the resins always 
found in rubber. To estimate the sulphur in the acetone extract, 
add 20 c. c. of a solution of pure sodium sulphide and caustic 
soda and heat the mixture on a water bath for an hour. Dilute the 
solution with warm water, and precipitate the fatty acids by add- 
ing a slight excess of barium hydrate. Filter, wash, and make up 
the filtrate to 300 c. c. and estimate the sulphur in an aliquot part. 



DETERMINATION OF SULPHUR. 227 

In determining the sulphur of vulcanization, the free sulphur 
must first be removed, and for this purpose, the acetone extract 
answers very well. In every case the sulphur of vulcanization 
should be estimated direct. The solution of rubber in nitroben- 
zene is therefore distilled under reduced pressure. The flask con- 
taining the non-volatile residue is then dried at 140° C, and then 
oxidized with fuming nitric acid. When the residue has finally 
dissolved, the solution is poured into a platinum dish, the flask 
being rinsed with warm nitric acid. The residue is then evaporated 
on the water bath, fused with carbonate of soda, dissolved in wa- 
ter, oxidized with bromine, acidulated with muriatic acid, and the 
sulphur precipitated with barium chloride. The sulphur in the 
asphaltum which is in the cold nitrobenzol solution is determined 
in a similar manner. 

The India-Ruhher and Gutta-Percha Trades Journal thus 
briefly summarizes processes for analyzing vulcanized rubber: 
''The analysis of crude rubber does not offer great difliculties. 
The sample has carefully to be taken, which is best done with the 
help of rollers, as used in rubber works. While kneading the rub- 
ber on the rollers, the rubber is mechanically purified by a water 
spray, and the loss in weight ascertained. Of the dried substance, 
5 or 10 grams are extracted by a Soxhlet apparatus with acetone 
for several hours, when the rubber resins pass into solution ; both 
the residue and ashes are then determined. Finished articles can 
generally be filed into friable powder. This is digested with alco- 
holic soda lye, filtered, and washed with hot alcohol ; the residue is 
boiled with water, the liquid always being passed through the 
same filter, then with hydrochloric acid, one filter being used, 
quickly dried, and weighed. The residue would still contain the 
bound sulphur, silicates, sulphates of barium, etc. What remains 
when sulphur and ashes have been allowed for, may be put down 
as rubber. " 



CHAPTER XiV. 

GUTTA-PERCHA -ITS SOURCES, PROPERTIES, MANIPULATION, AND 
PRINCIPAL USES. 

Gutta-percha, which was introduced into Europe from 
Singapore in 1843, was for awhile confounded with India-rubber, 
from which it differs in some very important particulars. It be- 
comes soft and plastic on immersion in hot water, retaining the 
shape then given it on cooling, whereupon it becomes hard, but 
not brittle like other gums. India-rubber, on the other hand, does 
not soften in hot water, and retains its original elasticity and 
strength almost unimpaired. The water, as such, exercises no 
softening action on Gutta-percha, the effect being purely one of 
temperature, which may equally well be produced by hot air, only 
somewhat more slowly. The degree of heat required depends 
upon the quality of the material, but even the hardest kinds be- 
come plastic above 150° F. Heated in air considerably above the 
boiling point of water, Gutta-percha decomposes and finally ig- 
nites, burning with a luminous smoky flame and emitting a pun- 
gent odor resembling that from burning rubber. If heated in a 
vacuum, gaseous and liquid products are obtained similar to those 
resulting from the distillation of rubber. The liquid which distils 
over consists chiefly of hydrocarbons of the terpene series, which 
form an excellent solvent for caoutchouc. The two most impor- 
tant are isoprene and caoutchine, which are identical with the 
liquids by the same names obtained from India-rubber. Since ^ 
these products can also be obtained from other sources, Dr. Eu- 
gene Obach and others have observed that they may yet form a 
stepping-stone in the synthetical production of India-rubber and 
Gutta-percha from the lower terpenes. 

A curious physical characteristic of Gutta-percha is that 
when it has been softened in water, although it is so plastic that it 
will reproduce the most delicate impressions, it will bear blows 
from hammers or allow itself to be thrown against a stone wall 
without being at all marred. The reason for this is that it con- 
tains a large amount of air. By placing the Gutta-percha under 
a bell jar immersed in mineral oil, when a vacuum is produced, a 

228 



COMPONENTS OF GUTTA-PERCHA. 229 

large amount of air is evolved from the gum, and it will be found 
to have lost the property of hardening on cooling, its substance 
being like a tough greasy leather. 

Nowhere on the globe have genuine Gutta-percha trees been 
found outside of a rectangular area embracing portions of the 
Malay peninsula, Borneo, Sumatra, and some adjacent smaller 
islands. Strange to say, the occurrence of these trees has not been 
established — though they may yet be discovered — in Java, the 
Celebes, or the Philippines. These trees belong to the natural 
order Sapotaceae; the principal genera and species will be noted 
further on. 

According to Payen's analysis, verified by later chemists. 
Gutta-percha contains three components: (i) a substance insolu- 
ble in cold and in boiling alcohol, which he termed pure gutta; 
(2) a crystaline white resin, soluble in hot, but not in cold alco- 
hol, which he called albane; (3) an amorphous yellow resin, which 
he named fluavile. Pure gutta is insoluble in ether and light pe- 
troleum spirit at ordinary temperatures, whereas both albane and 
fluavile dissolve readily in them. Gutta possesses all the valua- 
ble qualities of Gutta-percha, but in a much enhanced degree ; it 
becomes soft and plastic on heating, and hard and tenacious on 
cooling without being in the least brittle. But the resins them- 
selves are either soft at ordinary temperatures, or, when hard, 
quite friable. It is, therefore, gutta which forms the useful con- 
stituent of Gutta-percha, and the resins are only accessory com- 
ponents, which, although admissible, and perhaps even desirable 
in a comparatively small amount, yet have a decidedly detrimen- 
tal effect when they preponderate. Hence, in order to determine 
the technical value of a sample of Gutta-percha, it is necessary 
first to learn the relative proportion or ratio between gutta and 
resins. There must also be taken into account the zvater enclosed 
in the mass, and the coarser impurities — wood fibers, bark, sand, 
etc. — which are described as dirt. These components represent the 
loss or waste to the manufacturer. 

While the relative proportion of gutta and resins forms an 
important criterion for estimating the commercial value of a sam- 
ple, it is not in itself sufficient. Although the analysis of two dif- 
ferent specimens may give the same result, the physical and me- 



230 GUTTA-PERCHA. 

chanical properties, and, most important of all, the durability, may 
differ widely, owing to a dift'erence in their molecular constitu- 
tion. It will thus be seen that there are guttas and guttas. In 
addition to the qualitative analysis, it is necessary to scrutinize the 
gutta itself, which requires much judgment and experience. 
Analyses have been made of specimens which contained eight 
times as much gutta as resin; others contained about an equal 
amount of both, and in others still the amount of resin was three 
times that of gutta. Samples in which the percentage of resin 
reaches that of gutta, or surpasses it, are of a decidedly inferior 
description. These differences are due doubtless to the fact that 
the Gutta-percha of commerce is derived from trees of various 
species, and also in part to the treatment which the gum receives 
at the hands of the gatherers, who are suspected of mixing the 
product of different trees, to say nothing of adulterations of a 
more debasing character. 

The commercial classification of Gutta-percha is less satisfac- 
tory than that of India-rubber, since no standards have become 
fixed in the markets. While Para rubber, for instance, may be 
bought and sold by means of established designations, "Islands 
fine," "Upriver fine," and the like, no such practice exists with 
regard to Gutta-percha. Since all transactions in the latter are 
based upon samples, trade names and brands are little considered. 
However, "Macassar" and "Banjermassin," which are the names 
of districts producing Gutta-percha, were used formerly to indi- 
cate the highest quality, while "Sumatra" sorts were supposed to 
be less valuable, and Borneo the lowest of all. In a sense these 
designations have become merely commercial, no longer affording 
any indication of the origin of the Gutta-percha. At the same 
time, "Macassars" and "Banjermassins" might vary with every 
new arrival, so that one was not certain, in buying one of the 
sorts named, to obtain particularly good Gutta-percha; it might 
have been the very opposite. 

Innumerable sorts appear in the Singapore market — which 
is the center of the Gutta-percha trade — but Dr. Obach selected 
twelve of the principal brands as typical of all the rest, and di- 
vided them into four groups, for convenience in comparison, the 
best being named first. They are as follows, the designations 



PRINCIPAL BRANDS. 231 

being derived either from the countries of their origin or from 
the places of export: 

1. Pahang — from the Malay peninsula. 

2. Bulongan red — from Macassar, Borneo. 

3. Banjer red — from Banjermassin, South Borneo. 
( 4. Bagan goolie soondie— from Borneo. 

II. "Is. Goolie red soondie — from Serapong, Borneo. 

I 6. Serapong goolie soondie — from Serapong, Borneo. 
\ 7. Bulongan white — from Macassar, Borneo. 

III. ^8. Mixed white— from Borneo. 

( 9. Banjer white — from Banjermassin, South Borneo. 

i 10. Sarawak mixed— from Borneo. 

IV. -^11. Padang reboiled— from Sumatra. 
( 12. Banca reboiled — from Banca. 

Group 1 comprises the three best kinds, derived from trees 
of the genus Dichopsis (known in continental Europe as Pala- 
quium). Group II comprises three kinds of the second order, 
derived probabh^ from the genus Payena. Group III embraces 
the so-called "white gutta," of second and third grade, mostly of 
uncertain origin, but probably from Dichopsis polyantha. Group 
IV is made up of mixed materials, two of them being what is 
termed "reboiled'^ (an operation performed by the Chinese tra- 
ders, who buy up odd lots, soften the materials in hot water, and 
make them into a more or less homogeneous average mixture). 
The "Sarawak mixed" lots mostly represent a very useful second- 
class material ; the "reboiled" is decidedly inferior. This classifi- 
cation is based upon the results of 751 analyses of mixed lots, 
representing over 5,000,000 pounds of raw Gutta-percha, made 
by Dr. Obach, with a view to arriving at the relative proportions 
of gutta, resin, dirt, and water contained. The cleanest kind is 
the "Serapong soondie," which contains only 3^ per cent, of dirt, 
but it is rather wet, having more than 25 per cent, of water. One 
of the least favorable materials is "Banjer white," which contains 
33 1-3 per cent, of water and 15 per cent, of dirt, making in all 
nearly 50 per cent, of waste. When a raw material is very dirty 
and wet, it is noticeable on cutting the blocks open, and this is now 
the rule in the Singapore market. The blocks are then sorted 
out into several grades (two or three, sometimes more) accord- 
ing to their appearance, and valued accordingly. 

. A grade of Gutta-percha which is nearly white in color and 
very brittle is apt to contain a large percentage of resin, which. 



232 GUTTA-PERCHA. 

as already explained, renders it of little value. In explanation of 
some of the terms in the preceeding classification, it may be said 
that Gutta-percha is obtained principally by cutting down the 
trees and ringing the bark at intervals of 12 to 18 inches along 
the trunk. The milky sap soon fills the grooves cut into the bark, 
and, in the better varieties, soon coagulates, when it is scraped of¥ 
with a knife. In the case of inferior sorts, the milk requires more 
time to curdle, and has to be caught in receptacles placed under 
the tree. The collected milk is then gently boiled, either by itself 
or with the addition of water. The material obtained without the 
use of water is called a goolie, the other a gutta; but the two kinds 
are often mixed together. The goolie is more compact than the 
gutta, and has a dough-like smell. The word soondie is derived 
from the Malay term "Gutta-sundek," which is applied to the 
product of trees of the Payena species already referred to. 

The processes employed by manufacturers for cleaning raw 
Gutta-percha are either mechanical or chefnical. Those of the 
first class will first be considered. Generally speaking, the raw 
Gutta-percha is either first cut up in a slicing machine and then 
softened in hot water, or the lumps are placed directly in hot 
water and the soft material transferred to the washing machine. 
There it is washed with hot water for a longer or shorter time, 
and then passed through a strainer. Next, as a rule, it is washed 
once more, then put into a kneading or masticating machine, to 
consolidate it and remove the mechanically enclosed water, and 
finally it goes to the rolling mill, to be made into sheets. 

The slicing machine or chopper now used is pretty much the 
same as that proposed by Charles Hancock, of England, in his 
patent (No. 11, 575, O. L.) of 1847, except that it is is provided 
with a greater number of fluted and serrated knives, instead of 
only three plain ones, fixed in the slots of a heavy iron disc. The 
blocks of Gutta-percha are packed into a trough and then forced 
against the rotating disc, the knives in which cut the material into 
thin slices. 

The washing machine consists of an iron roller of star-shaped 
section, enclosed in a cylindrical shell provided with one or two 
projections, or ribs, against which the Gutta-percha is forced in 
going round. The cylindrical shell is enclosed in a large iron 



MECHANICAL TREATMENT. 233 

case, filled with water, which is heated by means of direct steam. 
The dirt, as it is washed off, falls through the lower part of the 
cylindrical shell into the outer case, whence it is drawn off once 
in a while. This machine is developed from that described in the 
English patent of R. A. Brooman (No. 10,550, O. L.) 

The Gutta-percha leaves the washing machine in a plastic 
state and passes to the straining machine — a strong iron cylinder 
with a perforated bottom, on which a number of discs of fine wire 
gauze have been placed. It has a piston which is driven home by 
hydraulic power, at a pressure of 1,500 to 2,000 pounds per square 
inch, squeezing the soft Gutta through the meshes of the gauze. 

The kneading machine or masticator resembles the washer, 
except that the roller is smaller in diameter, and the flutings are 
more numerous and not so deep. The Gutta-percha is kept hot 
during mastication and the water escapes in the form of steam 
through openings at the top. 

The mixing machine, introduced by Paul Pfeiderer, is similar 
to that used in the India-rubber, linoleum, and other similar in- 
dustries. It is provided with peculiarly-shaped blades, working 
against one another. The machine is used for mixing the various 
sorts of Gutta-percha, in order to obtain a material of any requi- 
site properties, and also for blending Gutta-percha with pigments 
or other ingredients. The rolls can be heated by steam, but heat 
is developed by the kneading process itself, and care must be taken 
not to overheat the material. 

The Gutta-percha is next rolled into sheets, usually between 
■| and ^ inch, and cut into lengths of 5 or 6 feet, and stacked away 
for use. The rolling machine takes the material from the mixer 
and squeezes it between parallel rollers, running it back and forth 
until it is cool and hard enough for cutting up. 

The average percentages of waste, shown by numerous anal- 
yses of the twelve brands of Gutta-percha catalogued on a pre- 
ceding page, are about as follows : 

Pahang 34 Bulongan white 43 

Bulongan red 35 White mixed 35 

Banjer red 44 Banjer white 47 

Bagan goolie sooudie 32 Sarawak mixed 44 

Goolie red soondie 27 Padang reboiled 44 

Serapong soondie 36 Banca reboiled 29 



234 GUTTA-PERCHA. 

The difference in the quaHty of various brands of Gutta- 
percha, measured by the relative proportions of gutta and resin, 
has already been mentioned. Of the sorts mentioned above, "Ban- 
ca reboiled" shows a comparatively small loss in cleaning, but it 
is the least valuable on the list, being low in gutta, whereas "Pa- 
hang," though losing more in the cleaning process, is by far the 
most valuable sort in the market, because so rich in gutta. Gut- 
ta-percha imported in recent years loses more in cleaning than 
formerly; Dr. Obach, in 1898, estimated the loss as almost twice 
as great as formerly. 

The chemical washing process was suggested by Charles 
Hancock, in an English patent, in 1846. He steeped raw Gutta- 
percha, cut into small pieces, in a solution of caustic alkali or 
chloride of lime, to neutralize the acidity and remove any unplea- 
sant odor. His experiments showed that the alkaline treatment not 
only reduced the percentage of dirt — that is, it was better cleaned 
than by the mechanical process — but lessened the capacity of the 
Gutta-percha for retaining mechanically enclosed water. But the 
treatment with chemicals requires great care and judgment, and 
thorough subsequent washing with water ; otherwise the material 
will be rendered perishable. 

Chemicals were also used by Obach for hardening Gutta- 
percha. The really valuable constituent of Gutta-percha being 
the gutta, the more a sample contains of the latter, the better it is, 
provided the gutta itself is of a good description. For certain 
purposes it is advantageous to improve the hardness and other 
mechanical properties of Gutta-percha, and this can be done by 
extracting the resin with a suitable solvent, which leaves the gutta 
itself intact. The raw Gutta-percha is first chopped and thrown 
on drying platforms gently heated from below by steam pipes. 
Or the pieces may be thrown into a rotating drum heated by cur- 
rents of warm air. They then go to a series of tanks in which 
petroleum spirit is used as a solvent for the resin. The spirit 
becomes charged with the resinous matters, and the resulting 
solution is distilled ofif, after which the material remaining is 
masticated as in the case of any other Gutta-percha. A speci- 
men treated by this process will remain quite hard under a tem- 
perature which will render other specimens soft and plastic. 



GREEN GUTTA-PERCHA— BAL AT A. 235 

Other liquids may also be used, as ether, and a saturated solution 
of carbon disulphide in alcohol. 

Instead of removing impurities from Gutta-percha by wash- 
ing it either with water or an alkali, this can be done by dissolv- 
ing the material into a suitable liquid, straining or filtering the 
solution, and then evaporating the solvent. Carbon disulphide 
has been used as the solvent, but with the effect of rendering the 
Gutta-percha perishable. 

Recently an article known as Green Gutta-percha has been 
offered to the trade, being extracted from the leaves of the trees. 
Several systems for extracting Gutta-percha from leaves have 
been described. That of Dieudonne Rigole involves the use of 
carbon disulphide ; that of Eugene Serullas the use of hot toluene 
as a solvent, after which the Gutta-percha is precipitated by 
means of acetone, instead of distilling off the solvent ; and that of 
Obach the use of light petroleum spirit as a solvent for leaves 
that have been previously crushed between rollers, the gum being 
reprecipitated from the solution on cooling below 60° F. The 
author of each process has devised apparatus for its operation. 

Many trees produce gums which have been experimented 
with in the hope that they would prove good substitutes for Gutta- 
percha, but none has proved of value except the "bullef tree, 
which yields Balata. The gutta contained in Balata is very strong 
and tough, being of excellent quality ; but the percentage of resin 
is large, and the material can be regarded as a substitute only for 
second-class, or perhaps even third-class. Gutta-percha. Balata 
is somewhat more flexible than Gutta-percha containing an equal 
amount of resin, which appears to be due to the softness of the 
resinous constituents. On becoming heated Balata behaves much 
like ordinary Gutta-percha. If plunged into boiling water it be- 
comes quite soft and plastic. If next immersed in cold water, it 
slowly hardens again, but still remains flexible and elastic, show- 
ing no signs of brittleness. Analyses of specimens of Balata from 
British Guiana, obtained from the London docks in 1889-94, 
showed an average loss of 13.8 per cent, of water, and 9.9 per 
cent, of dirt, or a total of 23.7 per cent, of waste. The respec- 
tive percentages of gutta and resin were 41.4 and 34.8. 

The specific gravity of cleaned Gutta-percha is practically 



236 GUTTA-PERCHA. 

the same as that of water, though varying with the relative pro- 
portion of gutta and resin, becoming lower as the percentage of 
resin increases. It may be affected, also, by the constitution of 
the resin and also of the gutta. The softening temperature of 
Gutta-percha depends entirely upon the ratio of gutta and resin. 
A specimen of which 60 per cent, was resin was softened at the 
temperature of 48° C. to the same extent as another specimen, 
containing only 2^ per cent, of resin, for which a temperature of 
55° C. was required. The time for the material to become hard 
again, after having previously been softened in hot water, depends 
in a like degree upon the proportion of gutta and resin. But the 
principal mechanical property of Gutta-percha with which the 
manufacturer has to deal is the tensile strength. A specimen hav- 
ing 45 per cent, of gutta and 55 per cent, of resin will break under 
pressure of 770 pounds to the square inch, whereas for another 
specimen, after most of the resin has been extracted with petro- 
leum spirit, nearly twice that breaking strain would be required. 
As for the elongation of Gutta-percha — i. e., the extent to which it 
will stretch before breaking — it is also affected by the percentage 
of resin, being in the last two cases, for instance, 490 and 500 
per cent., respectively, but it also depends on the nature of the 
gutta. 

The earliest practical use of Gutta-percha was for surgical 
appliances — for bandages, splints, and receptacles for vaccine 
virus. It is used for ear trumpets ; for the handles of surgical 
instruments, as it affords a firm grip and is preferable to wood 
for antiseptic reasons; in medicine, in the form (i) of a very 
thin tissue, (2) of sticks, and (3) of a 10 per cent, solution in 
chloroform ; for chemical purposes, in the form of tubes, pumps, 
syringes, bottles, and the like, and for ladles and tubes for hand- 
ling caustic alkalies and corrosive acids and liquids in chemical 
works ; and for mechanical purposes, as rings and cups for pumps 
and hydraulic presses and for driving-bands (belting). For the 
later purpose Balata is also used largely, interposed between can- 
vas ; such belts can be joined by means of a solution of Balata or 
Gutta-percha in carbon disulphide. Another application of Gutta- 
percha is that for taking impressions of medals, and also of the 
interior of large guns. Gutta-percha is also modelled into orna- 



USES IN INSULATION. 237 

ments in the shape of the leaves and petals of flowers, this being 
done by working the gum by hand in hot water with one or two 
simple iron tools. Such ornaments are often applied to the deco- 
ration of jars made of semi-porous ware, the whole being painted 
afterward. 

But the most important application of Gutta-percha is in the 
insulation of submarine and subterranean cables. Dr. Werner 
von Siemens first proposed Gutta-percha for insulating purposes 
in 1846, and in the next year he designed a screw-press, for the 
seamless covering of wires with that material, which is still in 
existence, while the principle of the press is still adhered to. Gut- 
ta-percha has been found to be very permeable to the X-rays, and 
it has been proposed to utilize this property to examine Gutta- 
percha-covered wires for the detection of defects in the copper 
conductor, particularly in "joints," or for finding air-bubbles. 
The X-rays may also be used for the detection of large foreign 
bodies in the raw Gutta-percha. Up to the end of 1896 no less 
than 184,000 miles of commercial submarine cables had been laid, 
embodying the use of Gutta-percha of a weight estimated at 16,- 
000 tons. Another 100,000 miles of cable had been laid by the 
various governments for military defense, which would require 
8,000 tons more, or a total of 24,000 tons for submarine cables. 
A further allowance must be made, for underground cables, street 
wires, etc., of 8,000 tons. The length of Gutta-percha-covered 
wires under the streets of London alone is 17,000 miles, corres- 
ponding to 375 tons of Gutta-percha. 

The electric properties of Gutta-percha depend chiefly on the 
nature of the gutta and to a less extent upon the resin ; but only 
very slightly on the relative proportion of these two components. 
They depend also upon the nature and amount of the impurities 
and on the water. The insulation resistance and inductive capa- 
city are little affected by the extraction of the resin. The insula- 
tion should be as high as possible, and the inductive capacity, 
for most purposes, as low as possible, but whereas the latter is 
mostly associated with other good qualities of the material, such is 
not always the case with a high insulation. A third electric prop- 
erty is called dielectric strength, or resistance to piercing by high 
voltages. A thickness of a little over -J inch of Gutta-percha breaks 



238 GUTTA-PERCHA. 

down with 40,000 volts, and one of about i-ioth inch with 28,000 
volts. 

Gutta-percha hardened by the extraction of its resin is used 
chiefly in the manufacture of golf balls. Gutta-percha for this 
purpose should be tough, elastic, and not brittle at low tempera- 
tures ; it should be specifically lighter than water, in order not to 
sink if dropped accidentally into a ditch. It is requisite that the 
proper grade of raw material be chosen and that the resin be ex- 
tracted as completely as possible. To test the elasticity of golf 
balls, a machine is used, consisting (i) of a perpendicular scale, 
divided into feet and tenths; (2) a clip, at the top, for holding 
the ball to be tested; and (3) an iron plate at the bottom. The 
object is to measure the rebound of the ball, when released from 
the clip and falling upon the plate. A ball made of Gutta-percha, 
of which 25 per cent, was resin, rebounded only to the point on 
the scale marked 30; a ball containing only 10 per cent, of resin 
rebounded to 45 ; and still another, having only a small percent- 
age, rebounded to 60 — ^the highest point reached. A ball of Ba- 
lata, having the resin thoroughly removed, rebounded to 59. 

Some figures will give an idea how greatly the physical and 
mechanical properties of Gutta-percha are affected by the ex- 
traction of the resin. Carefully selected specimens of a medium 
quality were cut fine and intimately mixed, and then divided into 
two portions. One portion was next washed in the ordinary way 
with water; the other treated with petroleum spirit until nearly 
all the resin had been extracted. The two specimens showed the 
following analyses : 

Gutta. Resin. Dirt. Water. Total. 

Cleaned in ordinary way 54.7 39.4 2.7 3.2 100 
Same material, hardened 93.0 2.8 2.5 1.7 100 

The different physical and mechanical properties of the two 
specimens are indicated in the next comparison: 

Ordinary. Hardened. 

Temperature when commencing to soften 37.7°C. 57.2°C. 

Temperature when commencing to harden 58.8°C. 9i.i°C. 

Time of hardening 17 min. 45 sec. 

Tensile strength — pounds per square inch 1592 5662 

Elongation — per cent 360 285 

The electrical properties, on the other hand, are but little 
affected, the insulation being practically the same as before, and 



, CAUSES OF DETERIORATION. 239 

the decrease of specific inductive capacity is probably due to the 
smaller percentage of water in the hardened material. 

The principal cause of the destruction of Gutta-percha is the 
absorption of atmospheric oxygen, which alters the gutta and pro- 
duces a brittle resin of quite a different nature to that originally 
present in the material. This destructive oxidization is greatly 
assisted by light, and by other causes — for instance, by any action 
tending to make the material porous, such as alternate wetness 
and dryness, the presence of substances which exercise a solvent 
action on Gutta-percha as a whole, or any of its components. 
Certain alkaline substances and decaying organic matters also 
appear to act injuriously, but frequently it is impossible to 
assign a definite cause for the decay of Gutta-percha. It is, how- 
ever, not merely manufactured Gutta-percha which undergoes 
these destructive changes, for raw material of the very best kind 
succumbs in time to the combined action of light and air. On 
the other hand, specimens of Gutta-percha are in existence which, 
after proper means of protection, have remained in good condition 
for more than fifty years. Complete immersion in water affords 
a good protection, for which reason submarine cores of Gutta- 
percha are more safely placed than underground wires. Another 
way of excluding the air, to some extent, is to varnish the Gutta- 
percha articles. When Gutta-percha is oxidized it becomes por- 
ous and full of cracks. If it is used for insulating wires, the insu- 
lation fails at such places, since the moisture penetrates the pores 
and fissures and establishes an electric contact with the conduct- 
ing wire. 

Some compounds containing Gutta-percha are very useful 
for different purposes, and a specially useful one, consisting of a 
mixture of Gutta-percha, colophony, and Stockholm tar, is known 
as "Chatterton's compound." It is used largely in connection 
with the manufacture of Gutta-percha-covered wires, as a bind- 
ing material between the copper conductor and the Gutta-percha 
covering, or between the different layers of Gutta-percha on the 
core. 

Willoughby Smith patented the following compound for in- 
sulating wires : One-fifth by weight of Stockholm tar and about 
the same weight of resin are put into a vessel with a jacket (or. 



240 GUTTA-PERCHA. 

preferably, a series of pipes) heated by steam; when properly 
melted the whole is passed through a wire gauze strainer "into 
another vessel similarly heated" ; three-fifths by weight of Gutta- 
percha, having by preference, been previously cleansed in the ordi- 
dinary way, and reduced into thin pieces or shreds, is then put 
into the heated vessel and mixed with the resin and tar. In this 
second vessel are stirrers, which are used to mix the whole uni- 
formly. 

Leonard Wray's cable compound was made of i part Gutta- 
percha, 4 parts India-rubber, 2 parts shellac, 2 parts flower of 
glass. This was used for underground wires. 

Gaullie combined Gutta-percha with Roman cement by means 
of animal gall, forming a plastic material, capable of being 
stamped and molded. 

Cooley mixed Gutta-percha with resin oil under heat, then 
mixed in carbonate of soda with roasted starch. To this compound 
he added asphalt to make it harder, or hyposulphite of lead, to 
make it softer. He also made a great many Gutta-percha com- 
pounds in which salts were present. These he steeped in water 
after mixing until they became soft and flexible. 

Charles Macintosh made a compound for telegraph wire from 
Gutta-percha, naphthaline, and lampblack. 

Charles Hancock boiled Gutta-percha in muriate of lime, 
passed it between heated cylinders, sifting the surface with rosin, 
in the production of a compound for complete insulation. An- 
other of his compounds was made of Gutta-percha, shellac, and 
borax. He also made Gutta-percha sponge by mixing with it 
carbonate of ammonia or alum and applying heat. He also made 
a hard Gutta-percha which was similar to vulcanite by mixing it 
with sulphur, putting it in molds and keeping the compound at a 
high temperature for several days. 

Duncan invented a great many compounds for Gutta-percha 
cement, many of which are now in general use. One suggestion 
of his was the mixing of Gutta-percha with Canada balsam and 
shellac, the resultant compound being a good cement capable of 
standing considerable heat and in no danger of becoming greasy 
on its surface. 

Robert Hutchinson claimed that he was able to render Gutta- 



VULCANIZATION. 241 

percha less liable to oxidize, to improve its elasticity, increase its 
tenacity, and diminish its liability to become sticky or tacky, by 
compounding it with lanichol or wood cholesterin. (See Lano- 
line). Forster deodorized Gutta-percha by mixing with it essen- 
tial oil, orris root, or gum benzoin. 

Liquid Gutta-percha is Gutta-percha dissolved in chloroform, 
to which a little carbonate of lead is added in the shape of a fine 
powder. After agitation, the mixture is set aside until the insolu- 
ble matter has settled. The clear liquid is then decanted. 

Spill, in order to prevent Gutta-percha that had been vulcan- 
ized from being attacked by grease, treated it to a solution of 
melted beeswax, hardening this coating with an infusion of nut 
galls. Godefroy mixed Gutta-percha with powdered cocoanut 
shell, claiming that it would stand a higher degree of heat, and 
was considerably more elastic. Day mixed pipe clay with Gutta- 
percha that is being vulcanized in order to prevent its sponging. 

The vulcanization of Gutta-percha, in spite of a common im- 
pression to the contrary, is something that can be easily accom- 
plished, and is analgous to the vulcanization of India-rubber. It 
can be done by mixing with free sulphur or sulphides that con- 
tain free sulphur, or by the use of chloride of sulphur. As the 
Parkes mixture attacks Gutta-percha very easily, the dipping for 
vulcanization must be very quick, the article being then allowed 
to remain in the air for some hours. The second dip can be a lit- 
tle longer, as the surface is less easily attacked than before. The 
vulcanized product is quite hard and will stand a high degree of 
heat. Chloride of sulphur mixed with bisulphide of carbon can 
also be incorporated in a solution of Gutta-percha and bisulphide 
of carbon, with the result that the Gutta-percha will be thorough- 
ly vulcanized. 

The late Robert Dick, of Glasgow, who was a successful 
manufacturer of Gutta-percha articles in the mechanical line, pro- 
duced many vulcanizable compounds of Gutta-percha of great 
value, some of which follow. He claimed that his compounded 
Gutta-percha retained the good qualities of the gum ; that is, that 
it was homogeneous and plastic at a moderate heat, but tough and 
hard at ordinary temperatures, and that it was just as valuable 
afterwards for mixing and molding over again. 



242 GUTTA-PERCHA. 

Compound No. i is described as the hardest and toughest, 
and may be used, in place of leather and vulcanized India-rubber, 
for tires, belts, pulley coverings, horse shoes, etc. No. 2 is softer 
and more elastic, and suitable for soles and heels of shoes, wring- 
er rolls, springs, playing balls, mats, etc. These goods are mixed 
in the usual way, and vulcanize in the masticator, but not enough 
to take away the plastic qualities of the Gutta-percha. For treat- 
ing this compound, a special masticator was devised by Mr. Dick, 
the rolling cylinders being hollow, and a Bunsen gas burner in- 
serted through one end of the hollow axle, while the gases pass 
off at the other, thus heating both roller and mixture. The outer 
cylindrical masticator is jacketed and heated with steam: 

COMPOUND NO. I. 

Pure cleaned hard Gutta-percha 28 

Pure cleaned tough selected Gutta-percha or Balata (preferably 

more rather than less) 11 

Pure cleaned " low white " Gutta-percha (preferably less rather than 

more) 9 

" Crumb " or ground good old vulcanized India-rubber 34 

Hardwood veneer dust 5 

Sulphur 6}4 

Zinc oxide (or zinc dust) 3 zi 

Flocking, or the cut fiber of cotton textile fabrics 3^4. 

Total 100 

COMPOUND NO. 2. 

Pure cleaned tough Gutta-percha 8^ 

Pure cleaned Balata or selected Gutta-percha 8^ 

Pure cleaned " low white " Gutta-percha 24 

" Crumb " or ground good old vulcanized India-rubber 33 

Hard ground veneer dust 5 

French chalk, powdered 6 

Sulphur 6 

Zinc oxide (or zinc dust) 3 

Flocking, or the cut fiber of cotton textile fabrics 3 

Alum, ground 3 

Total 100 

Another compound patented by Mr. Dick embraced the use 
of low grade African and Borneo rubbers, which, after cleansing, 
were mixed with Gutta-percha while still moist in hot water. Af- 
ter the mixing the compound is treated under a moist heat, where 
the temperature is 212° to 240° F., the result being a tough, plas- 
tic, fibrous dough. This compound is then, so the inventor claims, 
equal to any service for which the Gutta-percha and Balata com- 



COMPOUNDS. 243 

pounds are used. An important property in this compound is the 
shrinking quality which Gutta-percha possesses, while its power 
of cohesion rendered it especially valuable for insulating wires. 

Shepard mixed Gutta-percha with sulphur, exposed it to a 
heat varying from 300° to 350° F., admitting hot air, then com- 
bined it with sulphur and earthy matters. It was then vulcanized 
by Parkes's cold curing process. 

Parkes dissolved Balata and mixed it with 5 per cent, of chlo- 
ride of sulphur, diluted with mineral naphtha. Gun cotton was 
also dissolved to a pasty mass, in naphtha distilled with chloride 
of calcium, and the two solutions were combined, forming a soft, 
flexible compound. 

Childs vulcanized Gutta-percha by mixing it with sulphur 
and placing it in a vulcanizer containing hydrated lime, and then 
turning on heat sufficient to obtain enough steam from the lime 
to do the curing. 

Duvivier and Chaudet treated Gutta-percha with bromide of 
sulphur or chloride of sulphur, making it more elastic and less 
liable to be acted on by heat or cold. When acid vapors were 
formed during the operation, carbonate of sodium was mixed 
with the solution. 

Rostaing made Gutta-percha hard and unalterable by treating 
it, after cleansing, with caustic soda, which was thoroughly wash- 
ed out, after which it was combined with silicate of magnesia and 
treated with tannin, catechu, and other astringent matter. 

Keene cured Gutta-percha articles by exposing them to the 
fumes of sulphur or immersing them in a bath of melted sulphur. 

Charles Hancock treated Gutta-percha in a bath of boiling 
water in which was carbonate of potash, or muriate of lime, leav- 
ing it for an hour, and then mixing it with lead, glue, and bitu- 
men. His claim was that this treatment hardened the Gutta- 
percha, rendered it better adapted for bearing friction, and less 
likely to be oxidized. He also cured Gutta-percha by mixing 
with it sulphur, sulphides or orpiment, and applying heat. He 
gave as a compound for vulcanizing Gutta-percha 48 parts Gut- 
ta-percha, 6 parts golden sulphuret antimony, and i part sulphur, 
the compound to be boiled under pressure. 

Emory Rider mixed Gutta-percha with oxide of lead, heated 



244 GUTTA-PERCHA. 

it in open steam heat until the oily matters were expelled, then 
mixed it with hyposulphite of lead and cured it. 

Lucas prepared a printing- roll of Gutta-percha, first immers- 
ing the Gutta-percha in nitric acid, and then placing it for an 
hour in a solution of carbonate of soda, thus producing a tougher 
wearing surface. 

Barlow and Forster mixed Gutta-percha with Kauri gum 
and milk of sulphur for a cable coating. 

Macintosh immersed Gutta-percha in concentrated sulphuric 
acid for a number of seconds to harden the surface. He also 
mixed Gutta-percha with gun cotton, curing with sulphuric acid, 
claiming that the resultant compound was not likely to be affected 
by the heat of tropical climates. 

Analyses of common Gutta-percha, by Edouard Heckel and 
Fr. Schlagdenhauff en : 

Gutta 75 to 82 

Albane 19 to 14 

Fluavile 6 to 4 

Total 100 100 

Analysis by Payen: 

Gutta 78 to 82 

Albane 16 to 14 

Fluavile 6 to 4 

Total 100 100 

Gutta-percha is made of a mixture of hydrocarbons, and there 
is usually present a certain amount of oxygen. According to 
Granville H. Sharpe, F.C.S., its ultimate composition is: 

Carbon 86.36 

Hydrogen 12.15 

Oxygen 1.49 

Total 100. 

[Specific gravity, 0.96285 to 0.99923.] 
The primary analysis of Gutta-percha by Sharpe is: 

Hydrocarbon 79-7° 

Resin. ; i5-io 

Wood fiber 2.18 

Water 2.50 

Ash o. 52 

Total 100. 



CEMENT COMPOUNDS. 245 

Obach gives the following average results from a large num- 
ber of analyses of each of twelve leading brands or sorts of Gutta- 
percha : 

Gutta. Resin. Dirt. Water. 

Pahang 78.1 19-2 x.5 1.2 

Banjerred 67.0 30.2 1.5 1.3 

Bulongan red 68.6 29.0 1.4 i.o 

Bagan 57-5 40.9 i-O o-6 

Goolie red soondie 55.2 42.9 1.2 0.7 

Serapong 56.2 42.4 0.9 0.2 

Bulongan white. 52.2 45.4 1.5 0.9 

Mixed white 49.8 47.4 i.i 1.7 

Banjer white 51.8 44.1 1.8 2.3 

Sarawak mixed 55.6 40.9 1.8 1,7 

Padang reboiled 50.3 45.8 2.0 1.9 

Banca reboiled 46.8 51. i 11 i.o 

Another series of analyses by Obach relates to the constitu- 
tion of the resins in Gutta-percha, as follows : 

Albane. Fluavile. 

Carbon 78.76 80.79 

Hydrogen 10.58 11.00 

Oxygen 10.46 8.21 

Total 100. 100. 

Some typical Gutta-percha cement compounds follow : 

I. — For joining wood: Gutta-percha, 11 pounds; shellac, 3 
pounds ; Venice turpentine, 5 pounds ; pitch, i pound. 

2. — For uniting metals, glass, stone, and earthenware : Gutta- 
percha, 45 pounds ; shellac, 20 pounds ; gum mastic, 5 pounds ; 
oxide of lead, ^ pound ; storax, 3 pounds ; Venice turpentine, 26^ 
pounds. 

3. — For cementing leather : Gutta-percha, 4 ounces ; bisul- 
phide of carbon, 20 ounces ; asphaltum, i ounce ; common resin, 
I ounce. 

4. — Gutta-percha glue: Gutta-percha, i pound; rosin, i 
pound; litharge, i ounce; powdered glass, quantum sufficit. 

5. — Shoemaker's wax: Melt Gutta-percha, 20 ounces; add 
pitch, 58 ounces ; soap, 5 ounces ; rosin, 6 ounces ; beeswax, 5 
ounces ; palm oil, i ounce ; tallow, 5 ounces. 

6. — For preserving metals and other surfaces : Coal tar, 20 
pounds ; Gutta-percha, 5 pounds ; minium, 6 pounds ; white lead, 
7 pounds; pitch, 10 pounds; resin, 10 pounds; spirit turpentine, 
4 pounds ; sulphur, 38 pounds. 



246 GUTTA-PERCHA. 

7. — General cement: Make a solution of Balata of 5 ounces 
in I gallon naphtha, and another of Gutta-percha 5 ounces in \ 
gallon naphtha. Combine the two solutions and add 13 ounces 
resin or pitch and stir and mix thoroughly. 

THE ANALYSIS OF GUTTA-PERCHA. 

This of course refers to the analysis for the crude gum, and, 
to have the analysis complete, it should cover the amount of water 
present, the amount of foreign matters and impurities, the amount 
of ash, the amount of pure gutta, and the amount of resins. 

The water is easily determined by heating a known weight 
from the sample at a temperature ranging from 212° to 230° F., 
the loss in weight being the amount of water present. This is a 
common process in chemical analysis. In the case of Gutta-per- 
cha, it must be varied, as the sample is liable to oxidize even under 
examination causing an increase of weight. This is overcome by 
conducting the heating in a slow current of nitrogen, or carbonic 
acid gas. 

J. A. Montpellier devised an apparatus for this, which consist- 
ed of a special retort with a large opening which he used as a va- 
por bath and having a tubulure at its side. It is closed by a large 
cork, in which there are two holes, one for the tube which is to in- 
troduce the gas, and the other for the thermometer. The sample 
to be dried is placed in a crucible of porcelain or platinum sus- 
pended within the retort. As the water evaporates it is borne by 
the current of gas through a tube inserted in the side tubulure, and 
into U-shaped tubes, containing sulphuric pumice, which retain 
it. Further on the U tubes are connected with a Liebig tube with 
five bulbs containing pure sulphuric acid preventing the entrance 
of moist air after the apparatus cools, a further use being to make 
it possible to regulate the speed of the current of gas. 

The retort is immersed in an oil bath heated by a Bunsen 
burner. If carbonic acid is used it is obtained by the action of 
hydrochloric acid on marble chips produced in a Kipp apparatus 
followed by wash flasks, the first of which contains bicarbonate of 
potassium in solution, which is intended to stop the passage of any 
hydrochloric acid, and the second containing sulphuric acid at 150° 
to thoroughly dry the gas. To be absolutely sure that this gas is 



ANALYSIS. 247 

dry, a dessicator filled with sulphuric pumice is placed between 
the retort and the second wash flask. The operation of drying one 
gram with this apparatus, takes 6 or 7 hours. The determination 
of the amount of impurities which comes next may be effected 
very easily, by using M. F. Jean^s exhaust apparatus. A small 
part of the sample, from one-half a gram to a gram, is weighed, 
cut into small fragments, put in a filter, the weight of which is 
known, which in turn is placed in a platinum cone. This cone is 
then put in the extension of the apparatus; this extension com- 
municates by two tubes with the retort containing pure chloro- 
form. A condenser, in which a current of cold water constantly 
circulates in order to condense the chloroform vapor, is placed 
at the upper part of the extension. 

The retort rests on a sand-bath, very gently heated by a Bun- 
sen burner. Under the influence of the slight heat the chloroform 
evaporates, passes through one of the tubes, and drops on the filter 
containing the Gutta-percha, which it gradually dissolves. The 
solution, passing through the filter, then drips into the retort 
through the second tube. 

All the impurities remaining in the filter, it is sufficient to 
dry and weigh the filter to get the weight of the foreign matters, 
the drying should be done in the apparatus used in determining 
the amount of water. 

The next process is the determination of the amount of ash. 
In Gutta-percha this is always very small, as mineral matter is 
almost entirely absent from it, the quantity never exceeding one- 
half of I per cent. The amount of ash is determined by burning 
in a capsule of platinum or porcelain a known weight of Gutta- 
percha. 

The fourth step is the determination of the amount of pure 
gutta, and of the resins. Both fluavile and alban are soluble in 
absolute alcohol at the boiling point, and as pure gutta is insolu- 
ble in it, this is a very ready means of separation. The sample 
to be examined is cut in little bits, put in a platinum basket which 
is pierced with holes, and hung in a retort containing the alcohol. 
This retort is heated with a sand-bath or water bath, the vapor 
of the alcohol passing through a Liebig condenser and returning 
to the retort. The boiling is continued for 5 or 6 hours, with 



248 GUTTA-PERCHA. 

the basket immersed in the alcohol. It is then raised above the 
liquid, and the boiling continued for 5 or 6 hours more. The lat- 
ter part of the process removes the last traces of resin. 

The boiling operation being completed, the pure gutta to- 
gether with the impurities remains on the filter. There remains 
then the drying of the filter in the apparatus used in determining 
the amount of water and the weighing of it. The loss of weight 
shown by the Gutta-percha corresponds to the amount of resins 
increased by the weight of the water. Subtracting that weight, 
which has already been determined, the weight of the resins 
remains. 



INDEX. 



Abba rubber, 


26 


Alum,^ ... 


151 


Abies balsamea. 


118 


cure, . 


53 


Abyssinian gutta, 


29 


in coagulation, . 


44 


Accra rubber, 


18 


Alumina as a filler. 


61 


Acetate of lead. 


60 


Sulphate of, 


164 


Acetic acid, 


150 


Aluminum lanolate. 


168 


Achete juice, 


43 


Oxide of, . 


74 


Achras sapota, . 


28 


Amazonian resin rubber, 


27 


Acid, Acetic, 


150 


Amber, 


115 


Boracic, 


153 


Burmite, . 


118 


Carbolic, . 


154 


Oil of. 


177 


Chromic, . 


158 


Ambriz rubber, . 


20 


Citric, 


158 


Ambroin, 


99 


Formic, 


159 


Ammonia, . 


151 


Hydrochloric, . 


160 


Carbonate of, 


154 


Mimo-tannic, 


160 


Caustic, 


156 


Muriatic, 


160, 161 


Hydrochlorate of. 


159 


Nitric, 


161 


Muriate of. 


160 


Oleic, 


162 


Tungstate of. 


167 


Oxalic, 


162 


Ammonium, Chloride of. 


157 


Phenic, 


154 


Amorphous sulphur. 


54 


process of reclaiming 




Analyses of oil substitutes. 


88 


rubber, . 


III 


Analysis of Gutta-percha, 


244, 246 


Salicylic, . 


163 


lamp black, 


140 


Stearic, 


164 


rubber compounds. 


222 


Sulphuric, . 


165 


rubber substitutes. 


224, 226 


Tannic, 


166 


vulcanized rubber. 


215, 227 


Tartaric, 


167 


Angostura rubber, 


12 


Tungstic, . 


167 


Anhydrite, . 


61 


Acids, alkalies, and their de- 




Anhydrous paraffine oil, 


168 


rivatives, 


150 


Aniline, 


152 


" Acme " reclaimed rubber. 


113 


colors, 


136, 197 


Action of metals on rubber, 


209 


Anilines in coloring rubber 


135 


Adamanta, . . 


89, 115 


to be avoided. 


136 


Addah niggers, . 


19 


Animal charcoal. 


66 


A. D. R. gum, . 


89 


oils in rubber com- 




African rubbers, List of, 


15 


pounds, . 


168 


Shrinkage of. 


212 


substances in dry mix- 




Agalmatolite, 


60 


ing, 


85 


Air-brake hose, Testing, , 


216 


Anthracine, 


184 


Albane, . . . . 


229 


Antimony, . . . . 


60 


Alcohol as a solvent, . 


183 


Black, 


63 


Methylated, 


188 


Crimson sulphide of. 


145 


Ale, 


150 


Golden sulphuret of, 


56 


Alexite, . . . . 


99 


in curing rubber, 


50 


Algin gum, . . . . 


89 


Iodide of , . 


160 


Alkalies and their derivatie 


s, 150 


Oxide of, . 


75 


AUard's fireproof felt. 


203 


Penta-sulphide of. 


58 


Almeidina rubber. 


28 


Anti-poison act, German, . 


138 


Alstonia plumosa. 


32 


' ' Apo elasticon hyphasma, " 


105 



249 



250 



INDEX. 



Armalac, . . . . 


99 


Barium chloride. 


152 


Arsenate of potash, . 


152 


sulphide. 


54 


Arsenic as a filler, 


61 


Barta-Balli gum, 


32 


yellow, 


147 


Baryta, Carbonate of, . 


65 


Artemisia absinthium. 


177 


Barytes as a filler, 


63 


Artificial asphalt, 


116 


Baschnagel's devulcanizing 




elatente, 


89 


process, . 


no 


Gutta-percha, 


90 


Bastard or pseudo gums, . 


27 


India-rubber (Fenton 


's), 92 


Batanga ball, 


19 


rubber milk. 


209 


Bathurst rubber, . 


18 


sulphuret of lead, 


54, 61 


Bayin rubber, 


18 


whalebone. 


99 


Beeswax, 


117 


Artocarpus incisa, 


26 


Beira rubber, 


26 


Kunstleri, 


30 


Bell (P. Carter) on analyses 




Aruwimi rubber, 


20 


of rubber. 


222 


Asbestic, . . . ' . 


62 


Belting, rubber, Tests of, 


221 


Asbestine, . . . . 


62 


Benguella rubber. 


21 


Asbestonit 


105 


Benin ball rubber. 


19 


Asbestos, . . . . 


62 


Bonzol, 


184 


Ash, Bone 


64 


Benzole, 


184 


test of rubber substi- 




Beverly Rubber Works, 


no 


tutes. 


224 


Beyligky's devulcanizing 




Asphalt, . . . . 


"5 


process, . 


112 


Trinidad, . 


134 


Biborate of soda. 


153 


Assam rubber. 


22 


Bichromate of potash. 


153 


Assinee rubber, . 


18 


Birch bark tar, 


117 


Astrictum, . 


105 


oil, . 


168 


" Atalanta" reclaimed rubl 


jer, 112 


Biscuit rubber, 


17 


Atmoid, 


63 


Bismuth rubber cure, . 


SO 


Attalea excelsa, . 


43 


Bisulphate of potash, . 


153 


Attoaboa rubber. 


18 


Bisulphide of carbon, . 


184 


Aurelian yellow. 


147 


Substitute. 


185 


Australian caoutchonc, 


31 


Bitite, .... 


100 


Auvergne bitumen. 


116 


Bitumen, 


117 


Axim rubber, 


19 


Auvergne, . 


116 


Ayling's cold cure, 


51 


Black antimony, . 


63 






dye for rubber, . 


195 


Baka gum, . 


25 


German substitute, 


90 


Balata, 


27 


hypo, . 


64, 141 


as a substitute foi 




lead. . 


64 


Gutta-percha, 


235 


Mineral, 


141 


tree, . 


235 


Oak, . 


142 


Balenite, 


102 


pigments for rubber, 


141 


Ball, African, 


16 


pitch, . 


117 


Balloons, dyeing 


138 


Blacks, Carbon, . 


141 


Rubber, hand filled 


208 


Blandite, 


90 


Balsam, 


116 


Bleaching powder. 


163 


Canada, 


118 


Blown oils, . 


169 


of storax, . 


116 


Blue, Chrome, 


143 


of sulphur, 


116 


Cobalt, 


142 


Sulphur, 


59 


Indigo, 


144 


Tolu, . 


134. 


Molybdenum, . 


143 


Balsams in rubber com 




; ngments, . 


142 


pounding, 


115 


\ Prussian, . 


143 


Banana rubber, . 


26 


Yale, . . . • 


142 


Bangui rubber, 


20 


Boot and shoe manufacture 


5, 35 


Banigan's (Joseph) experi 




Bolas (Thomas) on shrink 


- 


ments, 


51 


age of rubber, 


211 


Barberry yellow, 


147 


Bolivian rubber, . 


12 



INDEX. 



251 



Bone ash, 

black, 

naphtha, 

oil, . 
Boracic acid, 
Borax, . 

as a solvent 
Bordeaux turpentine, . 
Bourn's (A. O.) devulcaniz 

ing process, . 
Brazilian birdlime, 
Brimstone gold, . 
British gum. 
Bromine rubber cure, . 
Bronzed appearance on rub 

ber, ... 
Brooksite, 

Brosium galactodendron, 
Brown pigments, 
Bucaramanguina, 
Bumba rubber. 
Burgundy pitch, 
Burmite amber, 
Burnt umber, 
Bussira rubber. 
Button lac, . 
Buttons rubber, 
Butyrospermum Parku, 

Cadmium, yellow, 
Calamine, , 
Calcium, white, . 
Calendering rubber. 
Calomel, 

Calotropus giganteus, 
Cameroons rubber, 
Cameta rubber, . 
Camphine, . 
Camphor, 

oil, 
Canada balsam, . 
Candle tar, . 
Canoe gums, 
Canvas sails, Waterproofing 
Caoutchine, . 
Caoutchite, . 
Caoutchouc aluta, 
Caoutchoucine, . 
Caoutchouc oil, . 
Cape Cattimandu, 
Cape Coast rubber, 
Carbonate of Ammonia, 

baryta, 

lead, . 

lime, . 

soda, . 
Carbon blacks. 

Bisulphide of. 

Substitute, 



64 Carbon Chloride of, . 

64, 140 Carburet of iron, 

187 Carnauba wax, 

169 Carn gum, . 

153 Carpodinus sanceolatus, 

153 Carriage cloth manufacture, 

185 Carrol gum, 

191 Cartagena rubber, 

Casein, 

III Caseum, 

26 Castilloa elastzca, 

56 Castor oil, 

117 Catechu, 

54 Cativo gum, 

Cattel's process for deodori 

196 zation, 

100 Cattimandu gum, 

25 Caucho, 

144 Caulbry's rubber cure, 

64 Caustic ammonia, 

21 potash, 

117 soda, . 

118 Caviana rubber, 

64 Ceara rubber, 
20 Celluloid, 

118 Potato, 

17 Cellulose, 

30 Cement manufacture. . 

compounds, Gutta 

147 percha, . 

65 Davy's universal, 
65 Portland, . 

43. 47 Theskelon, 

65 Cements, Rubber, 

32 Coloring, . 
19 Centrifugal method of coag 
II ulation, . 

185 Central American rubber, 

185 Shrinkage of, 
169 Ceramyl, 
118 Cerasin, 
118 Ceresine, 

33 Ceylon scrap rubber, 
203 Chapel (E.) on shrinkage 

186 of rubber, . . 212 
106 Chalk as a filler, . . • 65, 83 
100 French, ... 70 
186 Red, .... 80 
169 Charcoal, .... 66 

31 Chatterton's compound, 100, 239 
18 Chemical process of re- 

154 claiming rubber, . no 
65 Chemical Rubber Co., . m 
65 Cherry gum, . . . 119 
65 Chicle gum, ... 28 

155 China clay, .... 67 
141 Chloride, Barium, . . 152 

184 Chloride of ammonium, . 157 

185 calcium, . . . 157 



186 

65 

118 

119 

27 

38 

91 

14 

118 

n8 

9 

169 

156 

29 

203 

30 

13 

53 

156 

156 

155 

II 

15 
113 
103 

113 
41 

245 
130 
78 
109 
181 
136 

45 
13 
212 
119 
119 
119 
23 



252 




INDEX. 




Chloride carbon, . 


186 


Consolidated oil. 


170 


lime, . 


157 


Coorongite, 


31, 119 


sodium, 


157 


Copper, Effect of on rubber 


209 


sulphur rubber cure, 


. 53, 55 


Sulphate of, 


165 


Chlorine, Liquid, 


57 


Coralite, 


100 


rulaber cure, 


52 


Cork, .... 


67 


Chloroform, 


186 


Corkaline, . 


91 


Cholesterin, 




170 


Cork leather. 


106 


Christia gum, 




91 


Cornite, 


100 


Chromic acid. 




158 


Corn oil. 


170 


Chrome blue, 




143 


substitute, . 


91 


green, 




148 


Cornwall clay, 


67 


yellow. 




148 


Corundum, . 


68 


Citric acid, . 




158 


Corypha cerifera. 


118 


Clapp's (E. H.) devlucani 




Cost of rubber after shrink 




zation patents, 


III 


age. 


213 


Clay, China, 


68 


Cottonseed oil. 


170 


Fire, . 


68 


Cotton gum. 


"3 


Pipe, . 


77 


silicate. 


80 


Clothing manufacture. Rub 




Cow tree rubber. 


25 


ber. 


38 


Coyuntla juice, . 


44 


Coagulation of rubber. 


43 


Crape cloth. 


202 


Coal, Powdered, . 


79 


Cravenette process. 


199 


Coal tar. 


119 


Cream of tartar, . 


158 


naphtha, 


189 


Creosote oil. 


170, 187 


Cobalt, Blue, 


143 


Crimson sulphide of anti 




Codliver oil. 


170 


mony, 


145 


Cod oil. 


170 


Crystals of soda. 


159 


Colcothar, 


146 


Cumai rubber. 


25 


Cold curing process, . 


51 


Cutch 


156 


Colombian rubber. 


14 


Cyanide of potassium. 


159 


Colophane, . 


119 






Colophony, . 


119 


Dammar, Gum, . 


122 


Color of rubber, Natural, 


135 


Dankwerth's Russian sub 




Colored design for proofec 




stitute, . 


91 


fabrics, . 


197 


Davy's universal cement, 


130 


Coloring rubber. 


135 


Day, Austin G., rubber sub 




rubber surfaces. 


137 


stitutes, 


46 


Colors, Black, 


138 


Day, Horace H., early rub 




Blue, . 


142 


ber manufacture. 


51 


Brown, 


144 


Deodorization of rubber. 


85, 203 


for admixture with 




Dental rubber. 


41 


rubber, . 


197 


Dermatine, . 


106 


Green, 


148 


Dextrine, 


119 


Red, . 


144 


Dextrose, 


120 


White, 


137 


Diatite, 


100 


Yellow, 


146 


Diatomaceons earth. 


68 


Colza oil. 


170 


Dichopsis elhptua 
Dichopsis potyantha, . 


31 


Compo, 


67 


231 


Compounding rubber, Rea 




DieflEenbach's (George) rub 




sons for, . 


60 


ber cure. 


50 


Compounds for shower 




Dlppel's oil, , 


. 187 


proofing. 


199 


Druggists' sundries manu 




Kiel, . 


102 


facture. 


36 


Kirrage, 




107 


Dry-heat test of rubber sub 




Sorrel's, 




104 


stitutes. 


224 


Wray's, 




105 


Drying oils in rubber sub 




Congo oil, . 




178 


stitutes, 


87 


rubljer. 




20 


Drying rubber, . 


46 





INDEX. 


253 


Dry mixing, 


60 


Flour glass, phosphate, 


69 


Durango rubber, 


26 


Wheat, 


82 


Durate, 


106 


Fluoride of silicon. 


159 


Dutch Congo ball, 


20 


Fluvia gum, 


27, 33 


Dyera costula. 


27 


Formic acid. 


159 






Forsteronia gracilis, . 


31 


Earth wax. 


120 


Fossil farina. 


69 


Earth waxes in rubber com 




meal, . 


70 


pounds, 


115 


Frankenberg's waterproof 




East Indian rubbers, . 


22 


cloth, 


203 


Shrinkage of. 


212 


French asphalte. 


120 


Eaton's (A. K.) rubber cure 


50 


chalk, 


26 


Elasteine, 


91 


Congo rubber. . 


19 


Elastic glue. 


92, 120 


Gutta-percha, 


92 


Elaterite, 


120 


Navy tests of rubbei 




Electric facing, . 


68 


belting, . 


221 


Electrose, 


100 


talc, . 


82 


Elmer's (William) rubbei 




wool grease, 


172 


cure, . 


53 


Frost rubber. 


106 


Embossing rubher, 


196 


Fuller's earth. 


70 


Emery, 


68 






Equateur rubber. 


20 


Gaboon rubber, . 


19 


Esbenite, 


13 


Gambia rubber, , 


18 


Esmeralda rubber. 


14 


Gamboge, Yellow, 


147 


Essence of petroleum, 


171 


Gambria gum. 


27 


Ether as a solvent, 


187 


Garnet lac, ;■. 


121 


Eucaliptia, . 


171 


Gamier's (Edmond) alun 




Eucalyptus globulus . 


171 


cure, 


53 


Eucalyptus oil, . 


171 


Gas, Effect of on rubber, 


207 


Eucturbe edulus, 


43 


obtained from rubber 


207 


"Eureka" reclaimed rub- 




tubing, manufacture 


ber, 


112 


of, . 


208 


" Excelsior " reclaimed rub 




Gasoline, 


188 


ber. 


"3 


Gilsonite, 


121 


Extract test of rubber sub 




Glass, Soluble, . 


164 


stitutes, 


224 


Glucose, 


121 






Glue, .... 


121 


Falke's (Oscar) rubbei 


r 


Waterproof, 


99 


cure, . 


52 


Glugl OSS-gelatine, 


121 


Farina, 


68 


Gluten, 


122 


Fastening rubber to metal 


206 


Glycerine in rubber com 




Feldspar, 


68 


pounds, 


172 


Fenton's artificial rubber, 


92 


Goa gum, 


31 


Fiber, Lamina, . 


102 


Gold brimstone, . 


56 


Vulcanized, 


104 


Gold Coast rubber. 


18 


Fibers in rubber mixing, 


84 


Gold leaf applied to rubber 


196 


Fibrine-christia gum, . 


106 


Gold, Oxide of, . 


75 


Fibrone, 


lOI 


Golden sulphuret of anti 




Fichtelit, 


120 


mony. 


56 


Ficus elastica. 


10 


Golf balls, . 


238 


obligua, 


25 


Goodyear (Charles) vulcani 




Vogelzz, 


26 


zation process, . 


49 


Fillers in dry mixing. 


60 


triple compound, 


84 


Fire clay. 


69 


Gossypium herbaceum 


170 


Fish glue. 


120 


Grades of crude rubber. 


9 


oil, . 


171 


Grand Bassam rubber. 


18 


Flake rubber. 


17 


Graphite, 


70 


Flint, .... 


69 


Green, Chrome . 


148 


Flour of glass, . 


69 


dyes for rubber, 


195 



254 



INDEX. 



Green, Chrome Gutta-percha 235 
pigments, . . . 148 
ultramarine, . . 149 
Greytown rubber, . . 14 
Guatemala rubber, . . 14 
Guayaquil strip rubber, . 14 
Gum ammoniacum, . . 122 
anime, . . . 122 
arable, . . . 122 
asphaltum, . . 123 
benzoin, . . . 122 
camphor, . . . 122 
chicle, ... 28 
copal, . . . 122 
dammar, . . . 122 
elemi, . . . 124 
euphorbium, . . 124 
fibrine, ... 92 
frankincense, . . 124 
gamboge, . . . 124 
gambria, . . . 27 
goa, .... 31 
juniper, . . . i35 
Kauri, . . . 126 
lac, .... 125 
lini, .... 124 
Manila, . . . 126 
' olibanum, . . . 125 
Spruce, . . . 132 
thus, .... 125 
tragacanth, . . 124 
tragasol, . . . 125 
turpentine, . . 125 
Winthrop, ... 99 
Xanthorrhea . . 134 
Gums used in rubber com- 
pounds, . . . 115 
Gun cotton, . . . 113 
Gutta Bassai, ... 30 
Gutta-grek, .... 29 
Gutta Horfoot, ... 30 
Guttaline, .... 92 
Gutta-percha, Chapter on, . 228 
Analyses of, . 229, 244, 246 
" Banjermassin," . 229 
Brooman's patents, , 233 
cement compounds, . 245 
Chemical cleaning 



of, . 
Commercial classifi 

cation of, 
Components of, 
Deodorization of. 
Deterioration of, 
Dick's compounds. 
Effect of heat on, 
extracted from leaves 
Grades of, . 
Green, 



232, 234 

229 
229 
208 

239 
241 
228 
235 
230, 231 
235 



Gutta-percha, Chapter on, 
Hancock' s com- 
pounds, . . 240, 243 

Hancock's patents, 232 

hardened chemically, 234 

in compounds, . . 239 

in golf balls, . . 238 

in insulation, . . 237 

Liquid, . . . 241 

"Macassar" . . 229 

masticator, . . 233 
Mechanical cleaning 

of, .... 232 
mixing machine, . 233 
Montpellier's appara- 
tus for analyzing, . 246 
Obach's analyses of, . 245 
Pay en's analysis of, . 229 
percentages of waste. 233 
Properties of, . . 228 
Reboiled, . . . 230 
Resins in, . . . 229 
slicing machine, . 232 
Smith's compound . 239 
Sources of . . . 229 
Specific gravity of, . 235 
Substitutes for, . 87 
Natural, . 235 
"Sumatra" . . 229 
Uses for, . . . 236 
Vulcanization of . 52, 241 
White, . . . 230 
Gutta-shea, . . . . 130 
Gutta-sundek, . . . 232 
Gutta-susu, .... 23 
Gutta-trap, .... 30 
Gypsum, .... 70 



Half Jack rubber, . . 18 

Hall's (Hiram L.) devulcan- 

izing patents, . . no 
Hancock's Gutta-percha pat- 
ents, . . . 232, 234 



Hard rubber, 


99 


Decoration of 


195 


manufacture. 


41 


Substitutes for . 


99 


Harris's (Charles T.) rub- 




ber cure. 


50 


Hatch etine .... 


127 


Havemann's ( R. F. H.) 




rubber cure. 


52 


Heat in coagulation 


45 


Helenite, .... 


125 


Heifer process of coagulation 


45 


Helm's (John Jr.) rubber 




cure .... 


52 


Hematite, Red, . 


145 



INDEX. 



255 



Henriques (Dr. Rob.) an 




Kirrage compound. 


107 


alyses of rubber sub- 




Kommoid, . . . . 


93 


stitutes, 


226 


Kwilu rubber, 


21 


Testing rubber 


222 


Kyanized cloth process, 


202 


Heptane, 


188 






Hermizing process, 


51 


Lac, . . . , , 


126 


Hevea Brasihensis, 


9. 12 


Lactitis, . . . . 


102 


discolor, . 


12 


Lagos oil, . . , 


178 


Heveenite, . 


107 


rubber, 


19 


Heveenoid . 


106 


Lahou rubber 


18 


Honduras strip rubber, 


15 


Lake Leopold rubber. 


20 


Honeycomb sulphur, . 


57 


Lakes for coloring ruliber. 


197 


Hose, air-brake, Tests of, 


216 


Lallemantia oil, . 


173 


Hyaline, . . ' . 


lOI 


Lamina fiber, 


104 


Hydrochlorate of ammonia 


159 


Lampblack, Analysis of. 


140 


Hydrochloric acid. 


160 


for coloring rubber 


139 


Hydrochlorite of lime. 


159 


Lamu ball rubber. 


21 


Hydrogen, Peroxide of. 


162 


Landolphia, 


9,16 


Hydrosulphuret of lime. 


159 


Lanichol, 


173 






Lanoline, 


173 


Idrialin-Idrialit, 


125 


Lard oil. 


174 


Indian red, . 


145 


Lavender, Oil of,. 


176 


India-rubber compounds, 


60 


Lavandula vera. 


176 


leather, . 


107 


Lead, Black, 


64 


Infusorial earth. 


70 


Blue . 


64 


Insulac, . , , . 


lOI 


Carbonate of. 


65 


Insulated wire manufacture 


40 


Hydrosulphite of, 


57 


Iodide of antimony, . 


160 


Sublimed, . 


81 


zinc, 


160 


Sugar of, . 


164 


Iodine, 


57 


Sulphide of, 


141 


Ipomoea bona-nox. 


44 


White, 


83 


Iron pyrites. 


71 


Leatherine, 


107 


Isinglass, 


125 


Leatheroid, . 


103 


Islands rubber, 


II 


Lemon, Oil of. 


176 


Isolacit, 


lOI 


Liberian rubber, , 


18 


Isolatine, 


lOI 


Ligroin, 


188 


Isoprene, 


188 


Lime as a filler, . 


71 


Itaituba rubber, . 


12 


Carbonate of. 


65 






_ Chloride of. 


157 


Japan wax. 


173 


' Hydrochlorite of. 


159 


Java rubber, 


23 


Hydrosulphuret of, 


159 


Jelly, Petroleum, 


178 


in coagulation. 


44 


Jelutong, 


27, 33 


Juice, 


44 


Jenkins's valve packing. 


71 


Quick, 


163 


Jeve rubber, 


25 


Slaked, 


81 


Jintawan rubber. 


32 


Limeite, 


107 


Joselyn's (Henry W.) rub 




Linoxin, 


93 


ber cure, 


50 


Linseed oil. 


174 






Linum usitatzsszmum, 


174 


Kamerun rubber, 


19 


Liquid chlorine, . 


56 


Kamptulicon, 


107 


Liquor of flint, . 


160 


Kassai rubber 


20 


Litharge, 


72 


Kauri gum, . 


126 


Lithargite, . 


73 


Kelgum, 


93 


Litho-carbon, 


126 


Keratite, 


102 


Lithographic varnish. 


175 


Keratol, 


102 


Lithophone, 


139 


Kermes, 


71 


Little known rubbers. 


24 


Kickxia Africana, 


10 


Liver of sulphur, 


58 


Kiel compounds, 


102 


rubber, , 


21 



256 



INDEX. 



Liverpool pressed rubber, . 16 

Loanda rubber, ... 21 

Loango rubber, . . . 19 

Lomi rubber, ... 19 

Lopori rubber, ... 20 

Lugo rubber, ... 94 

Lump rubber, . . . 17 

Maboa gum, ... 26 
Machacon juice, ... 44 
Machine for testing air- 
brake hose, , . 216 
Machine for testing vulcan- 
ized rubber, . . 217 
Mackintosh manufacture, . 38 
Macwarrieballi gum, . . 31 
Madagascar rubber . . 21 
Madanite, .... 108 
Madeira rubber, . . . 12 
Maize oil, . . . . 170 
Majunga rubber, . . 21 
Male rubber tree, . . 28 
Manaos rubber, ... 12 
Mandarnva rubber, . . 26 
Mangabeira rubber, . . 15 
Manga-ice rubber, . . 26 
Manganated linseed oil, . 175 
Manganese, .... 73 
Peroxide of, . . 76 
Mangegatu gum, . . 32 
Manila gum, . . . 126 
Manoh twist rubber, . . 18 
Maponite, .... 94 
Marble flour, . . , 73 
Marcy's (E. E.) rubber 

cure, . . .49. 50> 5i 
Marloid, .... 103 
Massaranduba rubber, . 26 
Massisot, .... 73 
Mastic, . . . . 126 
Mattograsso rubber, . . 13 
Mayumba rubber, . . 19 
Mayall's (Thomas J.) rub- 
ber cure, . . . 112 
Mechanical rubber goods 

manufacture, . . 34 

Menthol 126 

Metal, Fastening rubber to, 206 

Metallined rubber, . . 108 

Metals, action of rubber on, 209 

Methane, .... 188 

Methylated alcohol, . . 188 

Mexican rubber, . . . 16 
Meyers's vulcanizing process, 52 

Mica, 73 

Micanite 103 

Milk of sulphur, . . 58 

Milling rubber, ... 47 

Mimo-tannic acid, . . 160 



Mineral India-rubber asphalt 

Orange, 

tallow, 

wax, . 

wool, . 

Minium, 
Mirbane oil, 
Mitchell's ( N. C) rubber 

reclaiming patents, 
Mixing rubber, 
Mold work, . 
Moist heat tests of rubber 

substitutes, 
MoUendo rubber. 
Molybdenum blue, 
Mongalla rubber, 
Moroccoline, 
Mountain flour 
Mozambique rubber, 
Mudar gum. 
Mule gum, . 
MuUee (William) in the 

hard rubber industry. 
Muriate of ammonia, . 
Muriatic acid, 

Murphy's (John) use of sul- 
phur for Gutta-percha, 
Musa rubber. 
Mustard oil, 
Myrole, .... 

Naphthaline, 

Naphthas as solvents, . 

Natural pitch, 

Neen rubber, 

Newbrough's (Dr. J. A.) 
vulcanizing com- 

pound. 

Nicaragua rubber, 

Niger rubbers. 

Niggers (crude rubber), 

17, 18, 19, 

Nigrite, 

Nigrum elasticum, 

Nip a fructicans, 

Nipa salt, 

Nitric acid, . 

Nitrobenzol, 

Nitro-cellulose, 

Notions in rubber. 

Novelty rubber, 

Nutgall, 

Nuts (crude rubber), 

Obach's (Dr. Eugene) clas- 
sification of Gutta- 
percha, 
Chemical cleaning of 

Gutta-percha, 
green Gutta-percha, . 



127 

74 
127 
127 

74 
74 

175 

III 

47 
40 

224 
12 

143 

20 

180 

74 
21 

32 
33 

52 
160 
161 

52 
26 

175 
127 

191 

189 

127 

33 



51 
14 
19 

21, 22 

103 

94 

44 

44 

161 

191 

114 

42 

94 
161 

17 



230 
234 





INDEX. 


257 


Ochre. Red, 


145 


Old C alabar rubber, . 


19 


Yellow, 


147 


Oleargum, . 


177 


Oil, Anhydrous paraffine, 


168 


Oleic acid, . 


162 


Birch, 


168 


Oleo resins, . 


127 


Bone, 


169 


Oleum succini. 


177 


Camphor, . 


169 


Olive oil. 


177 


Caoutchouc, 


169 


Orange ball rubber, 


21 


Castor, 


169 


mineral. 


74 


Cod, . 


170 


vermilion, . 


145 


Codliver, . 


170 


Origanum oil, 


177 


Colza, 


170 


Orinoco rubber, . 


13 


Congo, 


178 


Orpiment, 


148 


Consolidated, 


170 


Orris oil. 


176 


Corn, 


170 


Oxolate of lime, . 


162 


Cottonseed, 


170 


Oxolin, 


94 


Creosote, . 


171 


Oxide of aluminum, . 


74 


Dippel's, . 


187 


antimony, . 


75 


Eucalyptus, 


171 


gold, . 


75 


Fish . 


171 


iron. Red, . 


145 


Lagos, 


178 


lead, . 


75 


Lallemantia, 


173 


tin. 


75 


Lard, . 


174 


zinc, . 


75, 137 


Linseed, 


174 


Oxychloride of lead, . 


75 


Maize, 


170 


Oysters (crude rubber), 


17 


Manganated linseed. 


174 


Ozocerine, 


128 


Mirbane, . 


175 


Ozocerite, 


128 


Mustard, 


175 






Olive, 


177 


Pagodite, 


76 


Orizanum, 


177 


Pala gum, 


31 


Palm, 


177 


Palm oil. 


177 


Paraffine, . 


178 


Panama rubber, . 


15 


Petroleum, 


178 


Pantasote, . 


108 


Poppyseed, 


178 


Para rubber grades, . 


10 


Rapeseed, 


179 


Shrinkage of. 


211 


Rock, 


178 


Paraffine, 


128 


Rosin, 


179 


oil. 


178 


Russian mineral. 


179 


Paris white . 


76 


Shale, 


179 


Parkesine, 


94 


substitutes analysed, 


188 


Parkes's cold cure. 


53 


Vulcanized, 


180 


Parmelee's ' ' hermizing ' 




Walnut, 


180 


process. 


51 


White drying, . 


180 


Paste rubbers, . . i 


7, 18, 19 


of amber, . 


177 


Payen's analysis of Gutta 




lavender. 


176 


percha. 


229 


lemon, . 


176 


Pedryoid, 


108 


orris, 


176 


Pegamoid, . 


103 


peppermint, . 


176 


Penang rubber, . 


23 


rosemary. 


176 


Pentane, 


192 


tar. 


176 


Penta-sulphide of Anti 




thyme, . 


177 


mony. 


58 


turpentine, . 


191 


Peppermint, Oil of. 


176 


vitriol, . 


162 


Perchoid, 


95 


wormwood, . 


177 


Permanganate of Potash, 


162 


Oils, Blown, 


169 


Permambuco rubber, . 


I5 


Creosote, . 


187 


Peroxide of hydrogen. 


162 


used in rubber com 




iron, . 


^45 


pounds and solu 




lead, . 


76 


tions. 


168 


manganese, 


^6 


Okonite, 


108 


substitutes, 


'5 



358 


IND 


EX. 






Petrifite, 


76 


Puzzalona 


79 


Petrolatum, 


• 178 


Pyrites, Iron. 


71 


Petroleum as a solvent, 


192 


Pyroxiline, .... 


114 


Essence of, 


171 






jelly, . 


178 


Quick lime. 


163 


naphtha, 


190 






oil, . 


178 


Rangoon rubber, 


23 


paraffine, 


. 178 


Rapeseed oil. 


179 


Phosphate, Flour of, . 


69 


Rathite 


108 


of lime, 


76 


Reclaimed rubber, 


42,109 


of soda. 


163 


Red chalk, . 


80 


Phosphoric acid, . 


163 


hematite, . 


145 


Phosphorus, 


77 


Indian, 


145 


Physical tests of vulcan 




lead, . 


80 


ized rubber, 


215 


ochre. 


145 


Pickeum gum. 


33 


oxide of iron. 


145 


substitute. 


95 


pigments, . 


144 


Pigments for coloring rub 




Venetian, . 


145 


bar. 


135 


Reinhardt's analysis of rub- 


Pipe clay. 


77 


ber. 


225 


Pitch, .... 


129 


Rennet, 


163 


Black, 


117 


Resin, Adamanta, 


115 


Burgundy, 


117 


Resinolines, 


96 


Natural, 


127 


Resins contained in rubber 


182 


Plaster of Paris, . 


78 


in rubber compound- 




Plasters, Ingredients of. 


86 


ing. 


115, 130 


Rubber, 


42 


Oleo, . 


127 


Plasticon, 


103 


Retin asphalt. 


130 


Plastite, 


103 


Retinite, 


130 


Plumbagine, 


78 


Rhigolene, . 


193 


Plumbago, . 


78 


Richard's (Albert C.) rub 




Pneumatic tire manufac 




ber cure. 


50 


ture, . 


39 


Rider (John) on Gutta 




" Pongo " reclaimed rubber 


112 


percha vulcanization 


52 


Pontianak, . 


27 


Root rubber, 


26 


Poppenhusen's (C.) use o 




Rosaline, 


96 


rubber scrap. 


III 


Rosemary, Oil of. 


176 


Poppy seed oil. 


178 


Rosin 


130 


Portland cement. 


78 


oil. 




179 


Potash, 


163 


Rotten stone 




80 


Arsenate of. 


152 


Rubberaid, 




97 


Bichromate of, , 


153 


Rubberic, 




108 


Bisulphate of, . 


153 


Rubberite, 




96 


Caustic, 


156 


Rubber milk 


Artificial, 


209 


Potassium, Cyanide of. 


159 


Velvet 




T08 


Potato celluloid. 


103 


Ruberine, 




96 


Powder, Bleaching, 


153 


Ruberoid, 




96 


Powdered coal, , 


79 


Russian mineral oil, . 


179 


Preservation of rubbe 




Russian substitute. 


97 


goods. 


205 


Dankwerth's, 


91 


Presspahm, . 


104 






Prince's metallic paint, 


145 


Sal Ammoniac, . 


164 


Processes in coloring rub 




Saleratus, 


164 


ber. 


135 


Salicylic acid. 


163 


Proofing business. 


38 


Sal soda, . , 


164 


Prussian blue, 


143 


Salt, .... 


164 


Pumice stone. 


79 


in coagulation, . 


44 


Purcellite, 


95 


Saltpeter, 


164 


Purple dyes for rubber. 


195 


Saltpond rub 


ber. 


19 



INDEX. 



259 



Sandarac, 

Sapium biglandulosum. 

Sausage (crude rubber), 

Sawdust as a filler, 

Seed lac, 

Selenium, 

Shale oil, , 

Shellac, 

Shrinkage of rubber, 

Sieba gum, . 

Siemens (Dr. Werner von), 

pioneer in Gutta- 
percha, 
Sierra Leone rubber, 
Silex, , 
Silica, . 
Silicate, cotton 

of soda, 
Silicon, Fluoride of, 
Simpson's (E. L.) rubber 

cure . 
Sinapsis nigra, 
Sipnocatnpylos Jamesonia 

nus, 
Size, , . . . 
Slag wool, . 
Slaked lime, 
Slate, .... 
Sludge, 

oil resin. 
Smalts, 
Smith (Willoughby) on 

Gutta-percha, 
Smoking rubber. 
Soap in coagulation, . 

Substitutes, 
Soaps, .... 
Soda, .... 

Carbonate of. 

Caustic, 

Crystals of, 

Phosphate of. 
Sodium, Chloride of, . 

hyposulphite. 
Solubility of India-rubber 
Soluble glass, 
Sorel's compound. 
Specific gravity of rubber, 
Spermaceti, 
Spirits of turpentine, . 

wine in coagulation, 
Spruce gum, 
Stabilit, 
Stamp rubber. 
Starch, 

Stationers' rubber goods, 
Stearic acid, 

pitch, 
Stearine, 



131 Stibnite, .... 

29 Stick lac, .... 

21 Sticks ( crude rubber ), 

85 Stockholm tar, . , 

13 Storax, Balsam of, 

53, 80 Strips (crude rubber ), 

179 Sublimed lead, 

131 Substitute, Black German, 
211 Com oil, 

33 Dankwerth's Rus- 
sian, 
Tong oil, . 

237 Substitutes, Analyses of oil, 

18 rubber, 

80 Peroxide, . 

80 Soap, 

80 for Gutta-percha, 

164 hard rubber, 
159 India-rubber, 

Sugar of lead, 

51 Sulphate of copper, 

175 lead, , 

lime, 

25 soda, 

80 zinc, 

80 Sulphide, Barium, 

81 of alumina, 
81 antimony, Crimson 

179 lead, 

133 uranium, 

143 zinc. 
Sulphur, 

105 Amorphous, 

43 Balsam of, 

45 Chloride of, 

99 fumes in coagulation 

165 Honeycomb, 
164 in rubber substitutes 
155 Liver of, 
155 lotum, 
159 Milk of, 

163 Proto-chloride of, 
157 Sulphuret of antimony, Gol 

164 den, . 
181 lead, artificial, . 
164 Sulphuric acid, . 
104 Susu-poko gum, . 
213 

133 T abernoemontana Thursioni 

193 Talaing rubber, . 

45 Talc, French, 

132 Talite, . 
104 Tallow, 

41 Talotalo gum, 

81 Tamatave rubber, 

36 Tannic acid, 

164 Tannin, 

133 Tar, 
132, 179 Oil of, 



81 

131 
21 

133 
116 

17 
Si 
90 
91 

91 



223 

95 
97 

87, 99 

87 

87 

81, 164 

165 
81 

82 

164 
82 

54 
164 

145 
58, 141 

141 
59 
59 
58 
59- 116 
55 
44 
57 

224 
58 
58 
58 
58 

56 

54 

165 

33 

30 

33 

82 

82 

180 

30 

22 

166 

166 

133 
177 



26o 



INDEX. 



Tar, Stockholm . 




133 


Vaseline, 


180 


Tartar, Cream of, 


158 


Vegetable charcoal, . 


66 


Tartaric acid, 


167 


Vegetable pitch . 


134 


Tava rubber, . , 


21 


Vegetaline, . 


104 


Terra-verte, 


148 


Venetian red, 


145 


Terry (H. L.) on specific 




Venice turpentine. 


191 


gravity of rubber, 


214 


Vermilion, . 


144 


Textiloid, . 


97 


Versuvian white, 


39 


Theskelon cement. 


109 


Viscoid, 


104 


Thimble rubbers. 


17, 21 


Viscose, . . , 


104 


Thion, .... 


192 


Vitriol, Oil of, . 


162 


Thomas's (Joseph) vulcan 




Vitrite, 


104 


ized process, 


56 


Volenite, 


98 


Thomson (Sir William) or 


I 


Voltit 


98 


effect of metals ob 




Vulcabeston 


105 


rubber, . 


209 


Vulcanine, . 


59. 109 


Thyme, Oil of, . 


177 


Vulcanization of Gutta-per 




Tire manufacture. 


39 


cha, 


241 


Tires, Pneumatic, Testing 


India-rubber, 


49 


of, . . , 


216 


Vulcanized fiber. 


105 


Tirucalli gum, 


30 


oil, . 


180 


Tolu balsam, 


134 


rubber. Analyses of 


215 


Toluene, 


193 


Vulcoleine, . 


194 


Tong oil substitute. 


98 






Tongues (crude rubber). 


17 






Torres coagulation system. 


45 


Walnut oil, 


180 


Touchpong gum. 


29 


Wamba rubber, . 


21 


Tremenol, 


98 


Washing rubber. 


45 


Trinidad asphalt, 


134 


Waterproof fabric, A 




Tripoli, 


82 


porous, . 


203 


Trotter's (Jonathan), vul 




glue. 


99 


canizing process. 


49 


Watertown, Mass., tests oi 




Tumaco rubber, . 


15 


rubber goods at. 


218 


Tungstate of ammonia. 


167 


Wax, Carnauba, . 


118 


soda, . 


167 


Waxes in rubber com 




Tungstic acid. 




167 


pounds. 


"5 


Tuno gum, . 




28 


Weber (Carl Otto) on analy 




Turpentine, 




134, 180 


ses of rubber, . 


222, 225 


Oil of. 




191 


on resins in rubber, 


182 


rubber. 




98 


West Indian rubber, . 


15 


Spirits of, . 




193 


Whaleite, 


109 


Tuxpam strip rubber, 




15 


Wheat flour. 


82 


Twists (crude rubber). 


17, 18 


" White extract " reclaimec 


[ 






rubber, . , 


113 


Uelle rubber. 


20 


White, Barium, . 


138 


Ultramarine, Blue, 


142 


Calcium, 


65 


Green, 


149 


Calamine, . 


138 


Umber, 


146 


colors for rubber. 


137 


Burnt, 


64 


Fard's Spanish, 


139 


Unusual ingredients in dry 




Griffith's, . 


139 


mixing, 


84 


Whiting, 


83 


Upper Congo rubber. 


20 


Wilhoft's (Dr. F.) vulcan 




Upriver Para rubber, 
ifrostigma Gamelleira, 


II 


izing process, 


54 


26 


Winthrop gum, . 


99 






Woodite, 


109 


Valves, Preservation oi 


I 


Wood spirit. 


194 


rubber in, . 


205 


Wormwood, Oil of, 


177 


Vapor process of rubbei 




Wray's (Leonard) com 




cure, . 




208 


pound. 


105 



INDEX. 



261 



Xanthorrhea gum, . 
X-rays for analyzing Gut- 
ta-percha, . 
Xyloidin, 

Xylol 

Xylonite, 

Yale blue, . 
Yellow, Arsenic, 

Aurelian, . 

Barberry, . 

Cadmium, . 

Chrome, 



134 


Yellow Gamboge, 


147 






gutta, 


29 


237 




ochre. 


147 


134 




pigments, . 


146 


194 








"4, 134 


Zapotine, 


32 




Zinc, 


Borate of, . 


188 


142 




Carbonate of, 


138 


147 




Chloride of, 


158 


147 




Iodide of, . 


160 


147 




Oxide of, . 


137 


147 




Sulphide of. 


138 


148 




White, 


137 



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— in the world. No better goods are made 

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English Cliffstone Paris White 

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All Grades. 



We give special attention to the preparation 
of dry and finely bolted Paris White and 
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kinds of rubber goods, and can refer to any 
of the large manufacturers in any line. « « 



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The 
f H. F. Taintor Mfg. 

Co. I 



No. 101 BEEKMAN ST., 
NEW YORK, 



A D VER TI SEME NTS. 



STEPHEN P. SHARPLES, 

Analytical and Consulting Chemist. 

Tests and Analyses made of Reclaimed Rubber, Substitutes, 
Rubber Colors, Compounding Ingredients, Oils, Etc. 

,^jt Analyses of Vulcanized Rubbers. Water Analyses. .^^ 

13 Broad St., Boston, Mass. 



For Lustre Sheetings, Army Blankets 
and Surface Clothing, 

Cable's 

NA/ater 

Varnish, 

In use since 1884. 



The Best, Cheapest, and flost Durable Varnish for Rubber 
Covered Fabrics in Existence. 
Testimonials from Leading Rubber flanufacturers. 



SAMUEL H. CABLE, 

# JAMAICA PLAIN, MASS. 



MANUFACTURER OF 



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AISID 

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Samples Sent Rree. 



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Prices and Samples on Application. 




The Joseph Stokes 
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TRENTON, NEW JERSEY, U. 5. A. 

E. E. BUCKLETON, 

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ROBERT B. BAIRD, 

Crude Rubber, Reclaimed Rubber, Gutta Percha, 

and rubber manufacturers' supplies. 

67 CHAUNCY STREET, BOSTON, MASS. 

telephone no. 1212 oxford. 

Representative for New England and Canada 

OF 

Otto C. Mayer & Co., loewenthal Rubber company, 

CRUDE RUBBER. ^^^ RECLAIMED RUBBER. 



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ESTABLISHED 1883. 

LOEWENTHAL RUBBER COMPANY, 

(Successors to Loewenthal & Morganstern.) 

FtE30I-i.A.IM:HlD RXJBBEFt, 

HIGHEST GFRAOES. 

Office and Factory, 144-154 Provost St., 
JERSEY CITY, N. J., U. S. A. 



Benzols and napbtbas 

Made from coal tar. Special grades especially prepared tor 
use in manufacturing rubber goods and cements. Most 
efificient for solvent purposes, and for the cold vulcaniza- 
tion of rubber. Also makers of 

Carbolic Held 

Crystals, liquid and crude, for the preservation of rubber fabrics. 



Chemical Department, 

BARRETT MANUFACTURING CO., 

1205 Land Title Building, PHILADELPHIA, 

WM. H. SCHEEL, HENRY M. WOOLF, 

President. Vice Pres. and Gen-l M-g-r. 
GEORGE H. LINCKS, ROBERT C. BAIRD, 

Treasurer. Secretary, 

THE PREMIER TRIPOLITE COMPANY, 

Office. 159 maiden lane, 
NRW YORK, - NEW YORK. 
Tripoli of Superior Quality mined and milled at our own works. Special At- 
tention given to the requirements of Rubber Goods' workers. Crude, 
Ground, and Calcined Bolted Tripoli furnished in any quantity. 
S@° Samples sent on application. 



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RAYMOND RUBBER COMPANY, 

MANUFACTURERS OF THE FINEST GRADES OF 

MECHANICAL AND CHEMICAL 

RECLAIMED RUBBER 

For Manufacturing Purposes. 

Office and Factory, - - TITUSVILLE, NEW JERSEY. 

P. & B. Specialties for 

Rubber Manufacture. 

RUBEROID. — An artificial gam used as a substitute for India Rubber, works 
perfectly in hard or soft compounds, dry or wet heats. 

RUBERINE. — A liquid similar to rubber insulation, largely used in spreader 
compounds. 

P. & B. INSULATING TAPE. — Is water, acid and alkali proof. Is very sticky 
and never cracks or hardens. Is a perfect insulator. 

P. & B. ELECTRICAL COHPOUND.— Used for all kinds of electrical coating. 
Penetrates deeply, dries quickly. Absolutely water proof and acid proof. 

P. & B. ARMATURE FIELD AND COIL VARNISH.— Is elastic, moisture proof, 
and a perfect insulator. Has a hard, glossy surface, and will stand 300 degrees 
Fahr. before it shows signs of softening. 

P. & B. PRESERVATIVE PAINT and P. & B. INSULATING PAPER. 



THE STANDARD PAINT COMPANY, 

81 AND 83 JOHN STREET, NEW YORK. 



FORE 

SOFT 
8DLFH0R. 



Established 1841. Incorporated lasr. 



Bergen Port 

Sulphur Works 

ORIGINAL MANUFACTURERS OF 

Pure Soft Sulphur 

PREPARED ESPECIALLY FOR 

Rubber Manu facturers. 

T. (&. S. O. WHITE CO., 

28 Burling Slip, - - NEW YORK. 



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Chemists 



...AND... 



Chemical 



rianufacturers. 



Golden and Crimson Sulphurets of Antimony. 

Black "Hypo," very fine and uniform. 

India-Rubber Substitutes, White, Amber and 
Black. Eight Grades. 

Plumbagine for Oil-Resisting Valves. 

Red Pigment. Scarlet Stain. Vegetable Black. 
Yellow Pigment. Zinc Sulphide. 

Samples and prices on application. 

Instruction pamphlet written especially for rubber manufacturers, 
FREE. 



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CRUDE ar RUBBER 

^ ^^ m GUMS TESTED. **'^*^««**|of cEmf^js. 

Representing Lufbery & Chardonnier, Chauny, France, 

Manufacturers of Rubber Substitutes and Antimony. 

HENRV SMYTH E, 

Telephone No. 1443 Broad. - 3 SOUTH WILLIAH ST., N. Y. 

nXJBBEF?. SXJF F LIES. 

PAD/l "C/irriQ " trade mark for our ordinary grades of black and white substitutes, which are 
InlAfi IrHjllu. largely used by manufactiirers of bicycle tires, rubber clothing, druggists' 

sundries and mechanical goods. 

Asbestine, Asbestos Pulp, Barytes, Blue Lead., Black and White Substitutes, 
Bicycle Cements (all kinds), Carbon Bisulphide, Chloride of Sulphur, French 
Chalk, "^Golden Sulphide Antimony, Liime, Magnesia, Plumbago, Red Oxide, 
Shoddy and Ground Waste, Soapstone, Sulphur, Talc, Vermilion, Zinc Oxide, 
Zinc Sulphide. Send for Samples and Price. 

F. 0-A.R.TEPt BELL OO.^ 
CRUDE RUBBER, CHEMICALS AND SUBSTITUTES, 

150 NASSAU STREET, 

Telephone Number, 3906 Cortlandt. ^ ^ TVT ^^"VXT" "^V^ I'^^'f^'l^?" 



Cable Address, Bellsmith. I,ieber's Code Used. 



ESTABLISHED 1848. 



TOCH BROTHERS, 



MANUF.'VCTURERS AND IMPORTEKS OF 



CHEMICALS m PIGMENTS 

For the Rubber and Allied Industries. 

Oleum White, Special Vermilion, Lake Base, Grloss White, 

Zalk, Rubberite, Colors and Specialties. 

468, 470, 472 West Broadway, - - NEW YORK. 

Bisulphide of Oarbon 

and Ohloride of Sulphur, 

Especially prepared for India Rubber manufacture. 

Having had 20 years' experience in the manufacture of the above 
articles ; owing to the large sales during the past year, and on account of 
the growing demand resulting from its good results for cold cure, vaporiz- 
ing, and for makino- rubber substitute, I have reduced prices below com- 
petition. 

GEO. NA/. SPEIAIGHT, 

IS/lamufacturimg Chemist, 
lOS FUILiTOlST ST., - 1>THj"W "Y"0R,EC, IT. TT. 



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IX 



...ARIAL BRANDS... 

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Superior Qualities, made from best materials and by up-to-date methods. 

White Substitute. Black Substitute. ilono Chloride Sulphur, for making 

White Rubber Substitute. Proto Chloride Sulphur, for curing purposes. 

Bi=Chloride Sulphur, for making Brown Rubber Substitute. 

Also Waxes and Earths. Trial orders solicited. 

159 Maiden Lane and 37 Fletcher Street, NEW YORK, NEW YORK. 

Morris 8c Company, 

ESTABLISHED 1882. 
IVIAIMUF-ACXURERS OR 

Qroveville flilis Cotton Duck 
and Tire Fabric. 

We make a specialty of 

Rial) Grade Belting 
and l^o$e Duck 

For the manufacture of Mechan- 
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Cire fabric, 

Made from the finest grades of 

combed Sea Island, Egyptian, 

and Peeler Yarns. 

P. o. yardvill^e:, n. j., u. s. a. 




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write or telegraph us. Large stock 
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SECOND-HAND MACHINERY ONLY. 

Will take old Machinery in trade. 

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Until it is worked up into some marketable article. To do this 
machinery is required, and the better the machinery, the better and 
cheaper will be the finished product. The 



& 




ROYLB 

TUBING 

MACHINES 

Are model machines, with high produc- 
tive capacity. They greatly reduce the 
cost of making hose, tubing, and a 
great variety of mechanical goods. 
4®- SEND FOR CATALOGUE. 



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PATERSON, N. J., U. S. A. 



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Farrel Foundry & Machine Co., 

ANSONIA, CONN., U. S. A. 

ESTABLISHED 1848. 



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24-INCH 4-ROLL RUBBER CALENDER, BOX HOUSING, PATENTED. 

CALENDERS 

Of all kinds with rolls up to 36" diameter and 160" face. 

Washers, Refiners, Sheeters, Crackers, Mixers 
and Grinders, all Sizes, 

With cliilled. or sand rolls up to 22" and 26"x84", with or without 
roller bearings. 

HYDRAULIC BELT PRESSES, TWO OR MORE PLATENS, 
WITH PATENT HYDRAULIC STRETCHERS. 

Hydraulic, Multiple, Heel and Screw Presses Pumps, Accumulators, Etc. 

Rolls, Steel, Chilled Iron and Dry Sand. Belt Slitters, Bias Cutting 

Machines, Hose Wrapping and Belt Folding Machines. 

LirslOLEIUM MACHINERY. 

Machine-moulded Gears up to 10-inch pitch. 



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A HAND-BOOK FOR WORKS MANAGERS. 



THE COMPLETE COST-KEEPER 

Some Original Systems of 

SHOP COST-KEEPING or FACTORY ACCOUNTING 

togp;ther with 

An EJxposition of the Advantages of Accotmt Keeping by Means of Cards Instead of Books, and 

a Description of Various Mechanical Aids to Factory Accounting. 

Now compiled for the first time by 

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ESTABLISHED OVER 50 YEARS. 

Minerals, Clays, Talcs, Soapstone, Tripoli, Pummice Stone, 

Rotten Stone, Prepared Refined Lime, Oxide Zinc, 

Infusorial Earth, Silex, Manganese. 

ENGLISH CLIFFSTONE PARIS WHITE, without adulteration. 

( "VTorksliix^e Bi-aiid.) 

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Samples and quotations cheerfully sent upon request. 

240 AND 242 FRONT STREET, NEW YORK. 



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Edited by HENRY C. PEARSON. 



Furnishes all tlie current rubber news in tbe following lines : 

Rubber Boots, Shoes, and All Rubber Footwear. 
Mechanical Goods — Belting, Packing, Hose and Their 

Accessories. 
Syringes, Water-Bottles, and All Druggists' Sundries of 

Rubber. 

Surgical Goods and Specialties of Rubber. 

Vulcanite, or Hard Rubber for Electrical and Surgical Uses. 

Mackintoshes, Carriage Cloth, and Surfaced Clothing. 

Dental and Stamp Rubber. 

Tires and Cycle Accessories of Rubber, Moulded Specialties, 

Notions, Etc. 



Bach issue contains : 

Practical Articles on rubber matters of vital interest to the trade. 
New Goods fully described and illustrated. 

English, German, and French letters from special correspondents. 
Reports from correspondents at Para and other great crude rubber 

centers. 
A Complete resume of Rubber Patents. 
Trade Happenings among- the factories, at the selling agencies, or 

among the wholesalers and jobbers. 
Chats with and sketches of the leaders in the rubber trade. 
The Completest and best market report. 
Everything in the way of rubber information. 
Published on the first of each month at 120-122 Liberty Street, New 

York, U. S. A. 
Subscription Price, $3 per year. 
Advertising rates on application. 
Sample copy free. 



The India Rubber Publishing Co., 

New York Offices, 120-123 Liberty Street. 
London Offices, 222-225, Strand, W. C. 



XIV ADVERTISEMENTS. 



„Grummi-Zeitung" 

Dresden-Blasewitz. 

Haus Goodyear. 



FACHBLATT FUR DIE 



G-umnii-, Guttapercha- 

und Asbestindustrie. 



SOWIE DEREN 



Hilfs- und Nebenbranchen. 

ORGAN FUR DEN GESAMMTEN CHIRURGISOHEN, 
TECHNISCHEN UND ELEKTROTEGHNISCHEN HANDEL. 

Erscheint wochentlich (Freitag-s). Abonnementspreis M. 2.50, Ausland 

M. 3. — pro Vierteljahr. 

Annoncen die viergespaltene Petitzeile oder deren Raum 30 Pfg. 
Bei Wiederholungen Rabatt. 



RrolD3nummern Orstis. 



AD VERTISEMENTS. 



The Engineering Magazine 

Is an industrial publication of international reputation written by the leading 
authorities for men interested in the great industrial and manufacturing 
enterprises of the times. Besides the leading articles, each 
number contains a review of the most notable articles 
appearing in the American, British and Con- 
tinental technical press, and also 

AN INDEX 



TO 



Industrial Periodical Literature, 

Which is so classified that the titles of all the articles on any given subject can be 
seen at a glance. After each title is given a brief digest of the article, its 
length, the name of the author, and the name and date of the 
publication in which it originally appeared. 
Articles relating to factory construction are grouped under Architectural Engineer- 
ing and the sub-head Construction. Articles relating to steam engineer- 
ing and power production are arranged under the appropriate 
sub -heads of Mechanical Engineering. 
Every article indexed can be procured at small cost. Thus the whole range of 

current industrial literature is made available for each subscriber. 
For sample copy and further information address 

THE ENGINEERING MAGAZINE, 

New York Office: 120-122 Liberty Street. 
London Office: 222-225, Strand, W. C. 

30 cents a number. 
$3.00 a year. 



SEP 5 1899 



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LIBRARY OF CONGRESS 

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